(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Concrete and constructional engineering"

Univ. OF 
Toronto 
Library 



Digitized by the Internet Archive 

in 2010 with funding from 

University of Toronto 



http://www.archive.org/details/concreteconstruc05lond 



CQNCDETE 

'" AND 

CONSTRUCTIONAL ENGINEECING 



VOL. V . 1910 Nos. 1 to 12. 

A MONTHLY JOURNAL FOR ENGINEERS, 
ARCHITECTS. SURVEYORS & CONTRACTORS 
and all interested in CEMENT, CONCRETE, 
REINFORCED CONCRETE. FIRE RESISTING 
CONSTRUCTION and STRUCTURAL STEEL. 



INDEX 

K) 

VOLUME V. 

(Nos I to 12) 



n. 



5"' ^^' 

Piihlished at North British and Mercantile 'Building, 

Waterloo Place, London, S.W. 

1910 



CONCRETE 



AND 



COmTRUCTlONAL ENGmEERlNG 



X'tiLTME \', 



lyio. 



TA 



Published at North British and Mercantile Buildin 
Waterloo Place, London, S.W. 



INDEX 



BOOKS, NKW : 





Frosioi 


and 1-oresh 


ore 


Protection 






=te: Its. 


Conipositio 


% ai 


d Use ... 






.•te; PI 


lin and Rei 


nforced 






-te Stce 


1 Construct! 


on 




1 


Eleme 


nts of 


Reinforced Cone 


rcte Build 


"R 


Kncyc 


opgedia 


of Munic 


pal 




ita 


Knfr 


neering • . 








How 


to U-e 


Concrete 








Italia 


1 Book 


on keinfo 


ced 


Concrete 




Mode 


n Man 


ufacture of 


Por 




ent 


Pract 


cal Bu 


Iding Const 


uct 


on... 




Princ 


pies of 


Reinforced 


to 


icrctu 





Reinforced Co 



Re 



ed Co 



A Co 



Reinforced Concrete Construction 

Reinforced Concrete ; Theory and Practice.. 

Tables for Reinforced Concrete Work 

Technical Dictionaries in Six Languages .. 
Theory and IV-sign of Structur 



The. 



of St 



Portland Cen 



Trade 



Ma 



ufacture 
nufactur 



Beleian Cem 

Canal Lining of Cement Plaster 

Cement Brick. Mill Building- of 

Cement Wash 

Cement Works. M.achincry at .Am 
Customs .Authorities and " Naturr 
for Steamship Tanks 



Mor 
O 



Portl 

of 
Portland 



1 W'ork 

d Cement Concrete, t) 
d Cement, Le Chatelii 



nt, Br 



ndus 



Portland Cement 

Portland Cement, Manufacture of 
Portland Cement, Modern Manufac 
Portland Cement, Question of .Aera 
Portland Cement. Testing of 
Sea-water, Influence on Cement ... 
ing of Ce 



iling Test 

rd Specifi- 
■J.3. 704. 



Tests, Mo 



Clo 



et for Ce 



F.niTORI.AL NOTES: 
.Automobile Club. Royal ... 

Bridge, New City 

Bridge, Waterford 

British Standard Specificatit 



els Exhibii 



623 



Civil Engineers, I 

tion of - 

Concrete Institute 

Concrete. Summary of world 

Customs Authorities and " Xa 
Dijcks. Permanent Naval ... 

Farm Buildings 

Fire Resistance of Concrete 
Holloway Money Order Office 



790, S67 

Report of Institu- 

703 

54. .303. 789 

461 
790 

...' 866 
74. 54°. 6=3 



informat 
ral " Cement 



Internations 
Irish Local 

forced Concrete 
Local Government B 

Concrete 

London Building Act 



1 Testing .Associat 



Board and Rein- 
.rd and Reinforced 
Recent Amendments 



to 



Mi 
-Mor 



Cen 



n of Cement Users 

Our Fifth Year 

Portland Cement Industry in 1Q09 

Portland Cement, Specification lor ... 153. 

Port ofLondon Hues 

Reinforced Concrete. .American Views on ... 

Reinforced Concrete Chimneys 

Reinforced Concrete. Interim Report on ... 

Reinforced Concrete in 1909 

Reinforced Concrete in the Metropolis 

Reinforced Concrete. Irish Local Govern- 
ment Board and 

Reinforced Concrete. Local Government 
Board and 

Reinforced Concrete Practice and Design, 



Re 



aforced Concrete, Regula 



for Build- 



Standard Drawings 
Telegraph Poles 
Town Planning Con 
Waterford Bridge 
Waterproofing Cone 

GENERAL : 

American National 
L'sers. Report on 
Automobile Club. B 
Bowstring Girders. Tb 
Bridges. By D. B. Lut 
British Patents Relati 

Bungalows 

Camborne W'aterworks 
adford 



al 



Calculation of 
to Concrete 



Cen 



Works. Machii 



Chingford Re: 
Coast Defence Works... 
Cofferdams, Loughor A^iaduct 
Compressol Foundations ... 
Concrete Blocks, Buildings of 



921 

755 



Concrete Colu 
Concrete Hous 
Concrete Insti 

Concrete. Mix 
Concrete Und. 
Cottages. Com 



nd Pla 



Out; 



Earthquake D 



)f 212. 528. 601, 
688. 774. 844, 852, 909 
60. 373, 82s 
tted Surfaces ... 360 
>54, 3"3. 394. 6"5. 

789. 857 
ng by Hand ... 644 

=99. 413 

213. 688. 909 
imping Station, 



=r Wat 
erborongh 
indard Methods for Prepara- 
Concrete and Rein- 



443 



ice Posts 
■e Protection 
)ors for Bar 
Mt. Protecti 

ghwav Cons 



for 



of Concrete 
s and Granaries. 
n of Concrete fri 
re and OrnamenI 



... 732, »o5 

70, 74. 540, 623 

8S9 

" 533 

140,365.775.8,52 



Miiural Oils Mixed willi Coiiirctc 

I'apirs on Cciiitnt. Coiicrilc. Hiitl Reinforced 
Concrete (see under Recent Views). 

I'avements 457, 495, 53, 

PitlsliiirK Filtration Plant 

Pottery. Concrete 14. 

Keinhirceincnt. Choice of 55.1. 041, 744, 8i 

Retainini! Walls 19 

Ki^ini: Main on IJonna System, Norwich .. 
Ro.ids, Concrete lor 



Sa. 



Sea-water. Inllnencc on 


1 Com 


:rete 


SewaKi'. l-:ffcct on Coni 


Crete 


348, 


Skeleton Construction 


. Lo 


ndon Building 


.Act and 






Standard Notation for 


Con( 


:retc and Rein- 


forced Concrete ... 




-■, 30. 


Surface Finish, Coner« 


.•tc 


2.'5, 3to, 019, 901, 


Swansea, King's Dock 






'I'estinK Laboratories 


for' 


Concrete and 


Cement 




407, 


Town Planning Confei 


Fence 


(.99, 78;, 


Water KnKincers' Asso 


ciatio] 




Waterproofing Concreti 




■ 3»-=, 45". 497. 


NI)rSTRI.\L NOTKS 






Concrete Machinery ... 




60S, 



Concrete Stone Building Blocks 
Ccresit Waterproofing 
Sicgwart Poles and Pipes ... 



,mi:mor.\ni).a : 



Portland Cement Manuf.ictur 



Ba 


rs. Standard Specification 


f 


orcing 


Ra 


Ihs, Wood Green Public 


Bo 


nding New Concrete 10 Old 


Uo 


una Pipes, Tests on ... 


Br 


idgc. New Zealand 


Br 


idge Over the Tiber ... 


Br 


idge. Warrington 


Br 


idge, We.\ford 



Company's 
)r Portland 



Catal>.«u 



ining with Ce 
s 7-', '.S", ^-'s 
anks, Frai 



Closet for 
Cement Users, National Assoc! 

Cement Wash 

Chimneys, Tapering 

Cliff Improtement, Clacton 



A Cc 



Density of . 



Concrete in Pale 

Concrete Institute, The 220, 374, 

Concrete, Papers on 

Concrete, Proportioning Crushed Stone for 

Concrete Under Water 

Conduit. Mexico 

Constilting Kngincers, .Association of 

Culvert. Maidenhead 

Dams. Concrete 14S. 

Dry Rot. Prevention of 

I'lngineering Law, Lectures on 

l-"nginc-ers. Society of 149, 

llxhibitions 30., 

Kxhibition Stands 

Floors, To Prevent Dusting of Concrete ... 

F'rost. ICffect on Concrete 

Gravel v. Limestone in Concrete Aggregates 

Groynes, Move 

Gun-Fire. Resistance of Concrete to 

Hair Cr.acks in Concrete Surfaces, Re- 
moval of 

Hospitals. Concrete for F'evcr 

Houses. Painting of Concrete 147, 

Ily-Rib Test 

Lectures on Reinforced Concrete 

Machine Shops, Reinforced Concrete for ... 

Mill Building of Cement Brick 

Mining. Use of Concrete in 374, 

Motor-Car Houses. Concrete for 

New York Water Supply 

Parkhouse Prison. Concrete at 



Pier, 


, Broughty Ferrv 




Pier. 


, Ezremont 




Pine 


s. Cement-lined ... 




Pine 


5. Transport of Con 


Crete 


Pole 


s.. Concrete 




Port 


land Cement Tests 





Rcinfo! 
Reinfo 
Roads. 



ced Con 
ced Con 
Con 



etc, 



d Con 

ly Us. 



Crete lor 

Chingford 

Reservoir; Lowbiggins 

Road Congrcs--,, Irish 

Royal Institute of British Archil 
School Buildings of Reinforced Co 
Sewage .Action on Concrete 
Sewage Pipe>, Concrete r-. Stone 
Sewage Works, Concrete for 
Southampton Docks, Visit of Con 



Ste 



nt Flo 



Teignmouth Sea Defenc. 
Telephone Poles. Tests > 
Testing Materials, Amer 

Tests 

Tiverton Water Supply 
Town Planning Confers 



rs for 70. 

25, .3<>'. '>I9, 9"'. 933 



Society for ... 
••■298. 373. 4S<>. 



Not: 



nd Reinforced Con- 



Warehouse, Monte Video 
Waterproofing, " Ceresit " 
Waterworks. Castlewellan 

NKW USES; 

Barge in Reinforced Con 
Barn, Reinforced Concrel 
ckboa 



Chi. 



Me 



9=8 
447 
697 



Coal 

Concrete Blocks for Buildings ... 

Conduit, Woolwich 

Floating Dock 

Floors. Method of Construction 

Shuttering 

Fountain in Reinforced Concrete 
Garden Furniture and Ornaments 
Gasholder Tank at San Sebastian 
Mines, Reinforced Concrete in ... 

Made of Concrete Bio 



Co: 



Railing 
Railway Sic; 
Rifle Range 
Roundhouses 
Stadium. Sy 
Supports fo 



1 Work in Cement and Concrete 

'40, 

n Germany 






Rei 



icusc, U.S.A. 

.Aerial Transports 
:l forced Concrete ... 

T-Bcam Floors ... 



Wi 



Plant 



NKW WORKS: 

Armoured Tubular Floors at Belfast Foundry 
• Block Houses, Stockton-on-Tees 

Bow String Bridges. France 6S( 

Bridge, Cedar Rapids 

Bridge, Chin.iiford 

Bridge, Cotta-Dresden 

Bridge. Exmnuth 

Bridge, Grafton, Auckland 

Bridge, llartlake 

Bridge. Haydon 

Bridge, Kiel Docks 

Bridge. Mizen Head 

Bridge, Norwich 

Bridge Over Taff at Ccfn 

Bungalows 

Canal Basin, Bradford 

Centrepieces for Chicago Cement Show .. 

Church. Glasgow ... 

Church, Los Angeles 

Coal Bunkers, Stockport 

Coal Pocket. Athol, Mass., U.S.A 

Cottages. Newbiegen 

Culvert at Kilton 

Dam at Peterborough Pumping Station 
Ontario 

Dartford Brewerv Bottling Store 

Factory. Bailiff Bridee. Yorks 

Flooring. Sheffield Infirmary 

Flooring. Technical Institute, Belfast 

Galleries at Hull Cattle Market 

General Post Office 

Government Archives Denartment, Lille .. 

House of Concrete with Untreated Surface.. 

Lifeboat Slipway. Ackergill 

Manhole on Midland -and Great Northeri 
Joint Railway 



Momv Order Office. Molloway 
Parochial Hall. Wallsend-on Tync 

Silos, Hull ^ •■■ ■• 

Silos and Warehouses. Selby 

Swimming Bath, Dundee 

Theatre Roval. Barry Docks ^.. 
Tobacco Factory of Messrs. Carri 



By R G. CI 



itfa 



Wa 



nthai 



Wharf 


at Dives. 


France 










ir.CENT VIEWS: 
Bins of Reinforc 


:ed Cone 


rete 




By 




Dyson 
Brid.ee, 
British 

A. A. 
Cement, 


, Concrete 
Aluminiii 
H. Scott. 
Use in 


. By D.B, 
im Company 

M.S.A. ... 

.Architecture 


Li 


iten 
Woi 

By 


i- 



F. G. 

Baker . •■•, ■■ 

Chimney Construction. By t. R. Matthews, 

A.M.Inst.C.E 

Columns Tests with Concrete. By O. Withey 
Concrete and Reinforced Concrete. By E. P. 

Wells, J.P •■■ 

Ferroconcrete. By Robert G. Clark, Assoc. 

M.lnst.C.E •■■ 

Iron and Steel Preservation. By A. S. 

Cushman ^ - 

Notes on the Use of Portland Cement Con- 
crete. Bv S. Sills. M.Soc.Eng 

Portland Cement, Le Chatelicr Test with 

Boiling. By D. B. Butler 

Portland Cement, Manufacture of. By A. C. 



Da 



By 



Auden, 
Methods 



Reinforced Concrete 
A.M.Inst.C.E. 

Reinforced Concrete, Americ 
applied to. By Moritz Kahn 

Reinforced Concrete Construction. By 
H. W. Taylor 

Reinforced Concrete, History and Develop- 
ment of. By H. Kempton Dyson 

Rods Embedded in Concrete, Bearing Value 
of. By R. A. Cummings, M.Am.Soc.C.E. 

Sewage, Effect on Concrete. By S. H. 
Chambers 

Steel Frame Buildings and Reinforced Con- 
crete. By F. E. G. Badger 

Steelwork, Constructional. By S. Bylander... 

Structural Economy. By A. E. Slater, F.S.I., 
A.M.Inst.C.E 

Wabash Railway, Reinforced Concrete on 
the. By E. R. Matthews, A.M.Inst.C.E., 
and A. O. Cunningham, M.Am.Soc.C.E. 

Waterworks Engineering, Reinforced Con- 
crete in. By H. J. F. Gourlcy, B.Eng. ... 



.American National .Association of Cement 
Users' Report on 477, 

Automobile Club, Royal 75, 463, 

on for 

Beams; TestT under Repeated Loading '.'.'. 

Bins. Bv H. K. Dyson 

Bottling Store, Dartford Brewery 

Bowstring Bridges 

Bowstring Girders, The Calculation of ... 
Bridges 61, 64, 147, 322, 366, 304, 357, 440, 593, 
,96, 6S7, 691, 772, 845. 847, 850, 859, 863. 920, 



rd Spe 



British t'atents 45, 

Reinforced Con- 

--7. n', 303. 337. 

213, 

, Ornamental, for Chicago Cement 



Chimneys, Reinforced Concrete . 
Chimney Stacks. Lining of 

Church," Los Angeles 

Coal Bunkers 

Coal Pocket. Athol. U.S.A. 
Coal Trestle, Pennsylvania 

Columns, Test, with 

Conduit Woolwich 

Constantinople, Buildings at . 
Culverts .,, '^ 

Dock, Floating... 

Docks. Ipswich 

Dock Warehouses Mnrt.tii.i 
Earthquake Di 



for 
Farm Buildings 



cti. Reinforced Concrete 



Flo 



otball Stand, Bradfo 

Fountain 

Galleries. Hull Cattle 

Gas Tank 

General Post Office ... 



Gc 


.ver 


nment Archives Departm^ 


ent, Lille ... 


Or 


ana 


ry, Watcrford 




Ht 


.llo 


way Money Order Office 


...229. 261, 445, 


In 


stru 


iction in Practice and De 


•sign 


In 


'i"i 


m Report of Institution 


of Civil En- 
•■■703. 707. 798. 



Irish Local Go ._ 

Iron and Steel Preservation. By A. S. 

Cushman 

Jetty. Waterford 

Kiel Docks Works 

Lifeboat Slipway at Ackergill. N.B. ... 130 

Local Government Board and 155 

London Building Act and 5 

London County Council's Regulations on ... 
London County Council School of Build- 
Manhole on Midland and G.N. Railway ... 

Mines and 374. 46'i 

Papers on Concrete and Reinforcea Con- 



Power House 

Quays, King's Dock. Swansea 

Railings , 

Railway Construction 2 

Railw.ay Sleepers in Germany 

Reinforced Concrete. By A. C. Aude 

A.M.Inst.C.E 

Reinforced Concrete. Ameri 
Reinforcement, Choice of 
Reinforced Concrete and Co 

Wells, J.P 

Reinforced Concrete Construction. By H. W. 

Taylor 

Reinforced Concrete, Correspondence on 
37'. 537. 
Reinforced Concrete, Early Use of Concrete 



3JS 


and 

Reinforced Concrete. History and Develop- 


78s 


198 

4 28 


ment of. By H. K. Dyson 


765 


Reinforced Concrete in 1909 




Reinforced Concrete in Great Britain 


'85 




Reinforced Concrete, Quantities and Esti- 




507 


mates for. Bv H. K. Dyson 


3'S 




Reinforced Concrete. Special Uses for 


38' 




Reservoir, Chingford 


6'S 


434 


Retaining Walls '94. 274, 


383 




Rifle Range, Ostend 


697 


5'- 


Rising Main on Bonna System, Norwich ... 


891 




Rods, Bearing Value of. By R. A. Cum- 






mings, M.Am.Soc.C.E 


57 


834 


Roofing of Church of St. Aloysius, Glasgow 


285 




Roundhouses 327. 


77S 


569 


Roval Mail Steam Packet Co.'s Offices, 




.S4I 


Kingston, Jamaica ... -.. 


749 


539 


Sea Wall Construction 


543 


928 


Sewer Construction in San Francisco 


4S3 


447 


Silos '27, 211. 


79' 


531 


Standardisation Notation ... 2, 30, 3S2, 477, 


569 




Standardisation of Drawings ... ... 74. 


85 


662 


Standardisation of Quantities and Estimates 


3'5 


4.30 
'34 


Stadium, Syracuse 

Steel Frame Buildings and Reinforced Con- 


218 


691 


crete. By F. E. G. Badger 


19S 


248 


Supports for Aerial Transports 


527 




Swimming Bath, Dundee 


595 


925 


Tanks 694, 93". 


933 


574 


Telegraph Poles 530, 


604 




Telephone Poles 


147 


371 


Tests of Reinforced Concrete (see Tests 




769 


with Concrete) 






Trestles r?'. 449, 


621 


297 


United States, Reinforced Concrete in 


■85 


216 


Viaduct, Rotterdam Railway 


625 


216 


Viaducts, Bow String Girders and 


=48 



Warehouses 69. 204, 211. '. 

Water Towers 296, 364. , 

Water-works 512, , 

Waterworks Engineering. By H. J. F. 

Gourley 

Weslevan Hall, Westminster 

Wharf at Dives, France 

Wine Plant, California ■ 

TESTS WITH CONCRETE ; 

Beams under Repeated Loading 1 

Bonna Pipes ... ... ' 

Floors, Load Tests upon ' 

LB. & S-C. Railway Shops 

Telephone Poles : 

Tests on Reinforced Concrete Conducted in 
Great Britain 36, Co, 104, 178, Z53, 343, 373, : 



:r^ai 




CONCRETE 

AND 

CONSTDUCriONAL ENGINEEKING 



Volume V. No. 1. LONDON, JANI'AKV, 1910. 

EDITORIAL NOTES. 



OUR FIFTH YEAR. 

WITH llir present number this journal enters upon its fifth year, 'and 
Ihanks to the continued and increasing support we have received from 
our readers, and also owing to the ever-widening scope of the subject to 
whicii ovu' paper is devoted, we are now entering into a sjihere of even greater 
activity. 

This will be the fust year in wlm h our jniunal will apjiear as a monthly 
all through the year, as the change from a lii-monthly was only effected during 
the latter part of 1900. Our development into a monthly has been received 
most favourably not only at liunie Init aNci 1)\' dur many reailers in the fulonies 
and abroad. 

REINFORCED CONCRETE IN THE YEAR 1909. 

The columns of this journal will have borne testimony to the dexelojnnent of 
reinforced concrete and its uses during the past year at home, in our Colonies, 
and abroad. 

What has, jterluqis, been a matter nf primary im|)(irtaiur tn all those inter- 
ested in the subject in the L'nited Kingdom is the extent'to which the material 
is now being' employed for (Government works, notably by H.M. Office of Works, 
the Admiralty, and War Office. The example set by the Government Depart- 
ments in the application of reinforced concrete has been of the utmost value, 
for it has given that confidence which the material well merits, but which some 
of the ultra-conservative members of the technical professions have been slow to 
give it. 

The only unjileasaut feature in the Government's attitude during the past 
year has been the contmued adverse attitude of the Local Government Board in 
refusing to grant loan periods of adeciuate length where local authorities desire 
to use reinforced concrete. 

Of the many minor uses to which reinforced concrete has been ap])lied, 
the progress made in its application for railway sleejiers, telegraph poles, fence 
posts, pipes, etc., are, perhaps, the most notable instances. 

It may be anticipated that with 1910 the development will continue still 
further. Interest in the material is increasing in every direction, and the fact 
that it is not only practical, but also very economical, is making itself felt 
among building employers, who are even demanding its use in many cases. 

Legislation in connection with the use of reinforced concrete has also pro- 
gressed in the right direction during the past year, and with 1910 we may expect 
further improvements which will facilitate the use of the material still more. 



REPORT OF TH^ COSCRETE IXSTITUTE. [CQNCBETFJ 

In one direition mily we fear that its application has not progressed as we 
should have wish. .J. We do not find that architects of high standing are devoting 
sufficient -thought to the possibilities of reinforced concrete. If only some of 
the leaders in the architectural world were to strongly take up the matter, we 
believe the material would also find increased use amongst those wh<.> are rather 
preiiidiced as to its appearance in buildings. 

Speaking generally, however, the prospects for reinforced concrete are very 
bright, and building owners, members of the technical professions and the 
industries concerned, are likely to benefit materially by its greater application 
in the near future. 

THE REPORT OF THE CONCRETE INSTITUTE ON STANDARD NOTATION. 

We have received from the Concrete Institute a copy of their report on Stan- 
dard Algebraical Notation for Calculations. 

Our first impression on seeing the number of terms for which a symbol 
has been provided was one of alarm lest our already overburdened memories 
be further taxed by a horrible super-tax of inexplicable notation. We recollect 
that in the first paper ever read before the Concrete Institute Mr. Charles F. 
Marsh, M.Inst.C.E., said • — 

" There are so many different svnibuls required that the available alphabets 

are hardly sufficient for the purpose, and when trying- to deal with the calculations 

in a complete manne one sometimes wishes the Chinese alphabet were universally 

understood, as it mig-ht come in very useful when the Latin and Greek letters 

were all used up. " 

Upon examining the report before us, however, we notice that it is, on 
the whole. " just plain English," antl that no call has been made on the alphabet 
of the Celestial Empire. 

Cryptic and Egyptian hieroglyphics find no place in this report, and only 
a few of the best known Greek letters have escaped the censor's ban. 

A careful and critical reading of the report shows that the adoption of the 
initial letter, the use of significant subscripts, the discrimination between the 
uses of the small and capital letters, and the sparing use of the Greek alphabet 
are the four cardinal principles which have enabled the committee to replace 
the capricious preferences of individual authors bv the dictates of an impersonal 
logical necessity. 

The report is not complete, the hst is not perfect, but it will do very well to go 
on with. It is better than anything in the past, and it looks hopeful for the future. 

It is the newness of reinforced concrete which makes such a report possible. 
In some of the older branches of engineering the dead weight of tradition would 
retard the acceptance of even that which was desirable, rational, and necessary 
for progress. Now that a start has been made we hope that the principles 
formulated in this report will be extended to other branches of engineering. 

We learn on reliable authority that the principles laid down are winning 
wide acceptance, for they are simple, though the list may appear forbidding 
by its very length. 

Yet, after all, this forbidding aspect is more apparent than real, and arises 
solely from the fact that we are so used to long lists of symbols, most of which 
offer no intelligible clue to the quantity symbolised. 

It is noted that the essential principles of this report are applicable to any 



{B 



STANDARD NOTATION. 



language, allliDugh the actual details would, of rourse. varv according to the 
words abbreviated. 

I ' As a matter of fact, we notice traces of the initial letter ])rinci])le in German 
notation. For example : — 

6= Breite = breadth. Z = Zuj,'ii lensioii. 

b = Beton = concrete. ii = Nuninier = nuniljcr. 

t' = Eisen = iron. () = oben = lop. 

h = Hohe = hcifiht. ii - unlcii = IjoIIdih. 

/) ^ OrucU ^ compression. 
However, one swallow does not make a summer, and a few rational symbols 
do not constitute a system, be it German or French. 

The great advance made by this report is that it alisorbs all the natural 
abbreviations already existing in English notation, and consciously moulds all 
the rest on the same logical and intelligible basis. 

Engineers may well envy the chemists their universal notation, hut it must 
not be forgotten that chemists have a universal terminology, and ha\e oidy 
about seventy elements, not thousands. 

Engineers will have an international notation when they haxc an inter- 
national language. Till then a universal system of symbols must remain a -I'ade 
meciim for leisured and erudite linguists and for men with extraordinary memories. 

THE PORTLAND CEMENT INDUSTRY ^N 1909. 

Now that we ha\'e arri\ed at the end of the year it is ]H)Ssil>le. although the 
precise figures are not yet known, to estimate with fair accuracy the extent of 
the imports of foreign cement into the I'nited Kingdom during Kjoq, and it is 
gratifying to see that they show a very substantial falling off as comj^ared with 
previous years. The imports from abroad reached their zenith in 1904, when 
272,945 tons of foreign cement were cleared through our Custom Houses. .Since 
then the fall has been rapid, and in 1908 the imports were only 93,684 tons. 
For the year just closed they will not much exceed 65.000 tons. Of this quantity 
all but about 4.000 tons has come from Belgium, and of the latter practically 
the whole consists of the so-called "Natural" cement, the character of which 
has been so frequently described in these pages. 

In considering the causes which have contributed to this result, the steady 
fall in the price of first-class artificial Portland cements, which has been such a 
striking feature of the past two years, has undoubtedly had some effect. When 
the builder is able to obtain a high-class constructive material at little more 
than the price of the inferior Belgian cement he has less temptation to risk the 
loss which arises from failure of the work. After all, the quantity of Portland 
cement required in the construction of the average house is not great, and the 
maximum saving which can be effected by the use of the Bel.gian material, even 
assuming that the builder uses no larger proportion of it when mixing his 
concrete than he would use if a genuine artificial Portland cement were 
employed, is very small. But an even greater contributory cause will 
undoubtedly be found in the wider knowledge and experience which each addi- 
tional year has brought to those who were first tempted by the comparative 
cheapness of the " Natural " cement. A single bad failure may easily cause more 
loss than the apparent economy secured by the use of this material on a very 
large number of jobs, and when a man has suffered in this way he begins to find 

3 



PORTLAND CEMEST IX 1909. [C QNQ3ETE ] 

that cheajMiess ie not always synonymous with a low ])rire. Then, again, the 
information conci-rning the true character of Belgian " Natural " cements which 
has from tirae i;) time appeared in these pages has undoubtedly done a good 
deal to disc urage the use of a material of so uncertain and unreliable a character. 
Fir.al!\ , v.e think that a good deal is due to the wider adojition of the British 
Standard Specification for Portland cement, and a more careful insistence upon 
the compliance therewith. A larger jiroportion of engineers and architects now 
insist upon the frequent testing of the cements used upon their work, and even 
when they do not test the cement themselves, and do not employ one of the 
jMofessional experts to do the work for them, they insist on seeing the results 
of the manufacturer's own tests of the particular parcel from which the cement 
used on their work lias been sujijilied. When this has been done the professional 
man, who knows the reputation of the different makers, and who insists ujjon 
the cement being supplied only in packages bearing the name of the actual 
manufacturer, receives an assurance of prime importance. The Belgian 
" Natural " cement, however, cannot comply with the requirements of the 
British Standard Specification either in specific gra^■ity or in the soundness 
tests, and its more frequent examination has re\'ealed its interiorily so Ireqnently 
as to effectually discourage its use. 

But whilst imports of cement have thus fallen off so substantially, it is 
gratifying to find that the exports of British cements ha\'e been well maintained 
during the present year. There is a falling off, but this is v-ery slight, and we 
estimate the total exports for iqoq at 590,000 tons, or about 8,000 tons less than 
during 1908. The decrease is mainly in the exports to Egypt and to Canada. 
The former is accounted for by the financial crash which took place in that 
country some time ago, and which necessitated the strictest retrenchment in 
Government expenditure, in Canada, however, the decrease is due to the 
steady development of cement manufacture in the Dominion. As a set-off, the 
experts ha\'e increased to Me.xico and the various South American countries. 

REINFORCED CONCRETE TELEGRAPH POLES. 

It may ha\'e been observed that in recent issues we have been able to give a 
considerable amount of space to matters relating to reinforced concrete telegraj^h 
poles. We desire to point out particularly to our Colonial authorities the advan- 
tages of reinforced concrete telegraph poles compared with those of timber or metal. 

Originally, almost the monopoly of one inventor, we have lately referred in 
our columns to no less than four methods of making reinforced telegraph posts. 
Two hail from Germany, one from Denmark, and one from Switzerland, and we 
are glad to observe that if Great Britain has not been a pioneer in the matter 
of invention, at least one of these four methods has now been introduced into 
this country under favourable auspices, and the first of the reinforced concrete 
pole factories in England has just been started in Essex. 

There is no surer test of the-utility of a product than its advent from different 
directions and in different forms. 

There is no doubt that the application of reinforced concrete to poles used 
for telegraph, telephone, and similar transmission purposes is a step in the right 
^ direction, and that there is a wide field for the makers of poles and posts which 
combine efficiency with economy. 

+ 



SKELETON CONSTRUCTION. 






SKELETON CONSTRUCTION 

AND THE AMENDED 
i^ LONDON BUILDING 
ACT. 




..sm 



^^Mi^'^iMi 



The L.C.C. 

General Powers 

Act. 



JlOX 



y 'It- jrii^ie here presented summarises some of the lejdmi/ features of the ne'Uf 
Amendments to the London Building Acts^ for the excellent conception of tahtch the Metropolis 
is in the main indebted to the London County Council's Superintending Architects 
Mr. W. E. Riley. F.R.l.B.A.-ED. 



.\n article published in our issue of March, 1906, sets forth clearly some of the 
inconveniences and hardships endured for many years by architects, builders, 
and others owing to the unnecessary restrictions against the rational employ- 
ment of steel, which were perjietuated by those responsible for the London 
Building Act of 1894. 

Since the date of that article a Bill has been brought before Parliament 
by the London County Council conferring various powers upon that body, and 
containing in Part IV. authority to amend the London Building .^cts so as to 
bring those statutes into line with modern constructive practice. 

The amendments in question have now been fully considered, and. with 
some modifications, approved by committees of the House of Commons and 
the House of Lords. Consequently, they obtained the Royal Assent, and the 
much desired reforms have come into practical effect. 

In the present article we need not refer to the history of the movement 
whose aims have been realised, nor to the variou,s points which became subjects 
for controversy when the amendments were under consideration by the two 
Parliamentary committees. The amendments as originally drafted, under the 
advice of Mr. W. E. Riley, F.R.LB.A., were energetically opposed by the Royal 
Institute of British .\rchitects, the Institution of Civil Engineers, the Surveyors' 
Institute, and other bodies, but were very effectively supported by the British 
Fire Prevention Committee, whilst the battle waged round the subject was one 
of unusual technical interest. 

Our object, however, is not to deal with the bygones, but to give facts of an 
essentially practical character, and in what follows we devote attention simply 
to the nature and application of the main sections relating to the construction 
of metal frame buildings. In order that our readers may see at a glance the 
purport of the amendments embodied, we give in the subjoined table a synopsis 
of the sections added to the London Building Act, 1894, as also a Ust of the 
sub-sections of the all-important Section (22). The amendments comprise Sec- 



LONDON BUILDING ACT. 



ICQNCB ETEJ 



tiin (20). defining the " principal Acts," Section (21), interpreting this part of the 
Act. and Section V^). comprising the provisions as to metal skeleton construction. 
Section (22) has 35 sub-sections, as indicated below :— 

Sub- 



vith British Sta 



Secti' 
dard 



13D 
13E 



Sub- 
Section. 
LOA DS : 

Definition of dead load i8a 

Definition of superimposed load ... i8d 
Equivalents of superimposed floor and 
roof loads ... ... ... ... i8c 

Calculation of total load on founda- 
tion pillars, piers and walls ... ig 
Wind pressure ... ... ... ... 20 

WORKING STRESSES : 

Cast iron pillars and steel pillars ... 21A 
Wrought iron pillars ... ... ... 2iu 

Pillars under eccentric load ... ... 21c 

Pillars under eccentric load ... ... 21D 

Iron and steel (except in pillars) ... 22 

Rivets in shear 23 

FOUNDATION PRESSURES: 

Natural ground ... ... ... 24 

Concrete ... ... ... ... 25 

BRICK PILLARS: 

Proportions ... ... ... ... 26 

PRESSURE ON BRICKWORK ... 27 

CONCRETE : 

Power to prescribe materials and 
proportions ... ... ... ... 28 

ADDITION TO AND ALTERATION 
OF EXISTING BUILDINGS : 

Apphcation of skeleton construction 29 
STRUCTURAL METAL HEREAFTER 
STANDARDISED : 

Power to make regulations governing 
use ... ... ... ... ... 30 

DRA WINGS A ND CALCULA TIONS : 
Notice served on district surveyor to 
be accompanied with plans, sections, 
and stress calculations ... ... 31 

QUALITY OF METAL: 

Proof to be furnished to district sur- 
veyor 32 

LEGAL PROCEEDINGS : 

Appeal to petty Sessional Court ... 33 
.Appeal to Tribunal of .Appeal ... 3 + 
MODIFICATION OR WAIVER OF 
REQUIREMENTS « 



GENERAL: 

Steel to comply 
Specification 

Sustaining capacity of skeleton 
FIRE PROTECTION : 

External pillars 

External girders 

Internal pillars and girders 

GIRDERS : 

Compression flange to be secured from 
buckling 

Span in relation to depth and deflec- 
tion ... 

Connection of adjarent parallel girders 

Position where supporting enclosing 
walls ... 
JOINTS : 

Riveting and bolting ... 
WALLS : 

Thickness of enclosing walls ... 

Thickness of party walls 

Composition of mortar and concrete 

PILLARS— STEEL AND WROUGHT 
IRON : 

Thickness of metal and finish of ends... 

Joints 

Finish of foot ... 

Treatment of hollow pillars ... 
PILLARS— CAST IRON: 

Proportions and thickness of metal... 

Cap and base ... 

Finish of ends ... 

Joints ... 

Base 

PILLARS— GENERAL : 

Bedding of base 

Stress in and width of metal between 
pillars... 
FIRE-RESISTING CONSTRUCTION : 

Floors and staircases ... 
TREATMENT OF METALWORK : 

Cleaning and coating before use 

At the outset it should be pointed out that the amendments contained in 
Part IV. of the " London County Council (General Powers) Act, 1909," do not 
limit the metal employed in skeleton buildings to iron or steel. The latitude 
denoted was not at first prominently set forth, but is made clear in the linal 
form of the Bill. 

For instance, Section (22) makes it lawful to erect " buildings wherein the 
loads and stresses are transmitted through each storey to the foundations by a 
skeleton framework of metal," no particular description of metal being specified. 

.Again, Section (21) states that every pillar and girder of the kind contem- 
plated by the Bill shall mean a metal pillar and girder. 
6 



i/v^i-;^i^.'.!g!S^lFI SKELETON CONSTRUCTION. 

As the wording now stands, any structnial metal standardised l)y the Engi- 
neering Standards Committee after the passing of the Act may only be usc<l 
snhject to such conditi )ns as mav be established by the County Council, the 
latter proviso apparently being intended to govern the application of structural 
metals which at present have not been discovered, or. at any rate, which have not 
been standardised by the Engineering Standards Committee. 

The second paragraph of Section (21) permits a metal pillar to be built up 
of stanchions ])roperly riveted or bolted together. This is not quite satisfactory, 
for an assemblage of T-bars, I-bars, or channels bolted together would not repre- 
sent good work. However, as sub-section (10) of section (22) states that 
" rivets shall be used in all cases where reasonably practicable," and sub-section (31J 
I'lovides for the apjiroval of detailed drawings and calculations by the district 
surveyor, it may be taken that sufficient jjowers are gi\-i-ii for the frustration 
of attem|its in the direction of luijustihable economy. 

PROVISIONS WITH RESPECT TO SKELETON CONSTRUCTION. 

A jioint of considrraiilc impoitance is embodied in the opemiig ])aragra]ih 
<■! Section (2Z), where it is made clear that the provisions in the succeeding sub- 
sections shall apply not merely to the exterior skeleton framework of a building, 
but also to " the foundations, walls, floors, staircases, and other jiarts of the 
structure." Such of these details as are of metal actually form integral portions 
of the metal framework, and it is quite proper that they should be so dealt with. 
If the idea of some opjionents to the section had been accepted by Parliament 
the future of steel skeleton construction would have been seriously prejudiced. 
To provide for the strength of a skeleton consisting merely of outer columns 
a id beams it would be necessary to employ more metal than that required in a 
skeleton comprising interior members acting as effective bracing. Thus the 
tendency of the section as finally settled is towards economy, while at the same 
time affording a guarantee of sound design throughout the metal structure. 

STEEL TO COAIPI.V WITH BRITISH STANDARD SPECIFICATION. 

Sub-section (i) provides that all rolled steel used in skeleton construction 
shall be in accordance with the " British Standard Specification for Structural 
Steel." This stipulation will have the effect of debarring the employment of 
cheap foreign steel of low tensile strength, such as is frequently substituted for 
Hritish steel by persons who pay more attention to the price per ton than the 
plusical properties of material. The objection has been raised that disputes 
will probably occur relative to the precise methods of making tests and as to the 
fairness of the methods adopted by testing specialists. We really do not think 
the least trouble of the kind need be anticipated. All the leading steel makers 
and rolling mills now turn out rolled sections complying with the British Standard 
Specification, and are quite accustomed to submit their products to independent 
testing experts. Moreover, civil engineers always specify that steel flsed on 
important works shall be tested before acceptance, a condition which causes no 
difficulty in practice. Another fear expressed is to the effect that the legal 
establishment of the British Standard will lead to the employment of harder 
and more brittle steel with the minimum of ductility. This is a purely hypo- 



LONDON BUILDING ACT. (0C>NQ3CT^ 

thetical objection, which would not occur to anyone who has made himself 
familiar with the safeguards provided in the Standard Specification. 

An' omission of some importance is the absence of any specified standard 
quality for wrought iron, cast iron, and cast steel. Wrought iron is no longer 
used for the main elements of pillars and girders, but is still employed to a 
hmited extent in the form of small bars, bolts, and rivets. Hence the Bill 
ought to specify the standard with which the metal should comply. Cast iron 
is employed in the form of pillars and other structural details, and cast steel 
may enter into skeleton framework. These varieties of metal ought also to be in 
accordance \\ith some recognised standard. The absence of any safeguard with 
respect to the properties of the metals mentioned is somewhat unfortunate. 

FIRE PROTECTION. 

Sub-sections (3), (4), and (5) relate to the fire protection of metal pillars 
and girders throughout every skeleton building. All external pillars must be 
completely encased by incombustible material to the thickness of at least four 
inches, the whole being properly bonded together ; aU external girders must be 
similarly protected to the same thickness except at the underside and the edges 
of the flanges, where the protective casing need not be more than two inches 
thick ; all interior piUars and girders must be likewise protected to the thickness 
of not less than two inches. The onlj^ exception we take to these provisions is 
the implied recognition in sub-section (5) of " plaster " and of dense terra-cotta 
as efficient tire-resisting materials for covering interior pillars and girders. In 
all other respects the three sub-sections represent a welcome reform which might 
advantageously be extended to all iron and steel members employed in ordinary 
building construction. 

SPECIFIC PROVISIONS. 

Girders. — The concessions to economy represented by the permission in sub- 
section (8) to fix together by " iron separators and bolts " two or more adjacent 
girders or joists intended to act together is one which should be applied with 
discrimination. The House of Commons Committee properly stipulated that 
the connection of joists in this way should only apply to members closely adjacent 
to one another, but the sub-section is still rather unsatisfactory because it insists 
upon the use of iron for separators, thereby debarring steel in any form, and 
because it does not define the meaning of the term " separator." A piece of gas- 
pipe would answer the purpose after a fashion, and there is nothing to prevent 
its use. except perhaps an objection on the part of the district surveyor. 

Joints. — Sub-section (10), prescribing the use of rivets in all cases where 
reasonably practicable, may probably be apphed to hmit the employment of iron 
separators and bolts. Some opposition was threatened to this sub-section, on 
the ground that field-riveting would introduce a new trade into building opera- 
tions, and so cause much extra trouble and expense. Fortunately, as we think, 
the original wording was approved by Parhament, and so an assurance is given 
that bolted joints shall only be adopted in exceptional cases, instead of becoming 
the general rule. 

Walls. — The first four lines of sub-section (ii.\) embody the great reform 
long awaited by the advocates of skeleton building construction in this country. 



[/vS'?!;'nkV-k'i]^^ SiKl'^LETON CONSTRUCTION. 

Tlu'V provide that Ihe enclosing walls, or portions of external walls carried by 
nu'tal framework need not be thicker than 8i in. for the topmost 20 ft., or than 
13 in. for the remainder of the height. No permission is given to carry buildings 
to a greater elevation than that contemplated by previous enactments, so that 
the building of " sky-scrapers " is not legalised. But henceforward those 
adopting the metal framed system of construction will be freed from the vexa- 
tious restrictions established many years ago and confirmed by the London 
Building .\ct of 1894. 

To the i)rivilege thus conferred is added the option of employing a less 
thickness than Si in. in any case where such less thickness is prescribed under 
the Act of 1804. Sub-section (iib) demands that all party walls " shall be of 
the thicknesses prescribed by the principal .-Xcts." 

In the case of a detached building there would obviously be no party wall, 
and in consequence the mstal framework in the front and back walls would be 
efficiently connected and braced by the framework in the two end walls, as well 
as by the interior framework represented by floor girders. 

If, however, two or more contiguous buildings are erected all to the same 
general design, and divided up by partition walls for the convenience of separate 
owners or tenants, the dividing or party walls must be of the thicknesses pre- 
scribed by the principal .Vets, and need not include any metal framework, the 
absence of which will naturally tend to impair the completeness and continuity 
of the metal skeleton. In cases of the kind here contemplated architects will 
have to choose between two alternatives : (i) To design the skeleton framework 
for supporting only the front and back external walls, and sometimes for sup- 
porting also the two external walls at the extremities of the block ; and {2) to 
design a complete skeleton for all four walls of each jiortion ni the general buildmg, 
thereby making .twin curtain walls carried l)y the metal skeleton instead of 
building thick party walls of masonry. 

The first alternative suggests the possible development of an undesirable 
form of construction embodying detached lengths of front and back framework 
built into thick ])arty walls and not braced in a particularly efficient manner. 

The second alternative is conducive to the design of more rigid framework, 
but the additional cost involved will probably militate against its adoption. 

If it were not for the impossibility of providing for dual ownership ui one 
side of a m^tal skeleton the provision demanding thick masonry party walls 
would be unnecessary. The best mode of procedure is for every building to be 
designed with its own complete framework, which will then never be required 
to carry outer walls of msre than 13 in. thick. 

A satisfactory feature of sub-section (iic) is the demand that all Portland 
cement used shall be in accordance with the British Standard Specification, this 
stipulation being one that will obviously check the use of fictitious " Portland " 
cement now imported in large quantities from abroad. In party walls of the 
type demanded by the principal .\cts lime mortar may be employed as heretofore, 
except in parts immediately surrounding metal framework. 

Fire- resisting Construction.— Subsection (16) embodies a stipulation con- 
cerning the employment of fire-resisting materials, which is a useful addition to 



LOSDOX BUILDING ACT. 



.CONCRETE] 



the requirements stated in sub-sections (3) to (5). While duly grateful for 
these movements in the direction of fire-resisting construction, we hope that 
before many years have passed the application of the same principles will be 
made compulsory throughout all details of skeleton and ordinary buildings in 
the central districts of London. 

Loads. — After defining what is meant by dead and superimposed loads, 
sub-section (18) gives in paragraph (c) a statement of the estimated dead load 
equivalents of the superimposed loads on the floors and roofs of various classes 
of buildings. The equivalents here stated are intended for the purpose of 
calculating the loads on piUars. piers, walls, framework, girders, and other 
constructions carrying loads in buildings. As the paragraph is worded it would 
apply to all buildings were not its scope limited to metal skeleton buildings by 
the opening paragraph of Section (22). 

The provisions of the sub-section are summarised for ready comparison in 
the subjoined table : — 

T.\BLE OF De.\d Loads Equiv.alent to the Superimposed Lo.\ds on 
E.\CH Floor and on the Roof of Met.\l Skeleton Buildings. 



Class of Building and Intended Use 


Part of 
Structure 
Loaded 


Load 1 per sq. ft. 


Domestic Building (intended to be used wholly or 
principally for the purposes of human habitation 
or for domestic purposes) ... 

Office Btiildino (intended to be used wholly or 
principally for the purpose of an office or a 
counting house, or for any similar purpose) 

Workshop or Retail Shop Building 

Warehouse Building (not intended to be used wholly 
or principally for any of the purposes aforesaid) 

Every CLiss of Building (roof inclined at more than 
20° witli horizontal) 
(roof inclined at less than 20° with horizontal) 


Floor 

Floor 
Floor 

Floor 

Roof 
Roof 


70 lb. 

100 lb. 
112 lb. 

224 lb. 

2.S lb. -^ 
56 lb. ^ 



^ If the superimposed load is to exceed that specified in this column, such greater load shall be 
provided for pursuant to sub-section (2), and if the floor is to be used for a purpose for which a super- 
imposed load is not specified in this sub-section the superimposed load shall be provided for pursuant 
to sub-section (2) of Section (22). 

- Per square foot of sloping surface. 

'^ Measured on a horizontal plane 

The floor load equivalents covered by the sub-section will doubtless be 
found convenient for appro.ximate calculations relating to average practice. 
Of course, the loads will often be considerably greater than those stated, and 
to pro\'ide for such cases and other intended purposes an additional paragraph 
was inserted in sub-section (i8) to the effect summarised in footnote (') to the 
foregoing table. 

Comparison of the wording in footnotes {-) and (^), which are copied verbatim 
from the sub-section, reveals an apparent lack of clearness as to the precise 
meaning intended by the expression " per square foot of sloping surface." If 
we mterpret the meaning correctly the first paragraph denoted would be im- 
]-)rovfcd by omitting the words we have printed in square brackets and by inserting 
the words we print in italics, thus : — 



TTxc 



SKELETON CONSTRUCTION. 



" l'\)i ci roiil the plane of which inclines upwards at a greater angle than 
20° with the horizontal the superimposed load (which for this purpose shall be 
deemed to include wind pressure) shall be estimated at 28 lb. per sq. ft. [of 
sloping surface] measured on the inclined plane of the roof." 

As so modified the wording would be free from ambiguity, and harmonise 
with that (if the next paragraph, which reads : — 

" Fur all other roofs the superimposed load shall be estimated at 56 lb. 
per sq. ft. tneasured on a horizontal plane." 

Apart from the foregoing point the new regulations defining the super- 
imposed roof loads to be taken into account by designers are not quite satisfactory. 

To begin with, we have two arbitrary classes divided by an imaginary 
line, and including : (i) Roofs inclined at any angle between 20° and go° with 
the horizontal ; and (2) roofs inclined at any angle from 20° down to 0° with 
the horizontal. 

Notwithstanding the considerable range of inclination prescribed the super- 
imposed loads are to be taken at the uniform unit \-alues of 28 lb. and 56 lb. 
for the two classes respectively. 

In the case of Class I. the only superimposed loads contemplated are 
evidently wind pressure and the weight of snow. Taking as a basis the horizontal 
wind pressure of 40 lb. persq. ft., the customary equations give for various inclina- 
tions from 20° to 60^ with tile horizontal the normal pressures persq. ft. stated below. 



Inclination of Roof 


Normal Wind Pressure 


20 


1 8-4 lb. 


25 


22-6 ,, 


30 


26-5 „ 


35 


30-1 ., 


40 


33-3 .. 


45 


36-0 ,, 


50 


38-1 ., 


55 


39-4 .. 


60 


40'0 ,. 



Allowing 5 lb. per sq. ft. for the possible snow load on a slope of 20°, and 
assuming the snow load to be progressively reduced to zero at the slope of 60°, 
we find that for roofs of I and \ pitch the prescribed load of 28 lb. per sq. ft. 
would not be far wrong, while for greater inclinations it is obviously quite 
niadequate. 

In the case of Class II. the snow load increases and the wind pressure 
decreases with the reduction of slope, but taking the snow load at the uniform 
value of 5 ]b. per sq. ft., and assuming the horizontal wind pressure of 40 lb. 
per sq. ft., we have the following values : — 



Inclination of Roof 


Normal Wind 
Pressure 


Snow t.oad 


Total Suix'nmpdsed 
Load per sq. It. 


20 dcg. 1 8-4 lb. 

15 ., :4-- .. 
10 .. 9-(i .. 

5 5 ■ 1 - • 
, o-o ,. 


5 lb. 


23-4 lb. 
19-2 ,, 
14-'; .. 



LONDON BUILDING ACT. [CQNCCETE] 

Of course, some provision must be made for loads other tlian wind pressure 
and the weight of snow upon flat roofs and roofs of low pitch. The minimum 
of 56 lb, per sq. ft. is reasonable for a fiat roof, and equally unreasonable for 
one with the inclination of 20°, the latter point being demonstrated by the fact 
that, according to the new Act, the minimum load on a roof with the slope of 
20° i' is onh' 28 lb. In other words, the load suddenly jumps up a quarter of 
a hundredweight as soon as the imaginary line of demarcation between the 
tw-o classes has, been passed. 

Rational methods of computing roof loads are perfectly simple, and it is 
to be regretted that the new Bill should legalise incorrect rule-of-thumb methods 
of computation. 

Except so far as influenced by the preceding sub-section, the provisions of 
sub-sections (10) and (20) are judicious additions to the London Building Acts. 

Working Stresses. — Sub-section (21) as originally drafted defined the per- 
missible working stresses for cast iron, mild steel, and wrought iron pillars on 
the basis of the alternative ratios — length to least width, and length to least radius 
of gyration. The first of these ratios is now obsolete, and affords no reliable 
index to the effective proportions of a pillar. The second ratio can be calcu- 
lated without trouble, the process being facihtated by the fact that the radii of 
gyration for every British Standard section are given in the handbook published 
l)y the Engineering Standards Committee. A few experimental calculations 
will show that the safe loads for pillars computed by both of the alternative 
methods may differ by fully 20 per cent. In a large building with pillars under 
heavy loads the discrepancy might easily run to 200 tons per column, repre- 
senting a total discrepancy amounting to thousands of tons. Thus the 
authorisation of an admittedly inaccurate method might have involved much 
waste of metal and consequent increase of cost without an}' advantage. For 
these reasons we are very glad to find that in its final form the Bill makes the 
ratio of length to least radius of gyration compulsory for determining the stresses 
in all metal pillars. This is an amendment upon which the professional advisers 
to the County Co\mcil are to be congratulated. 

Two new paragraphs (c) and (d) in sub-section (21) make suitable provision 
for eccentric loads on pillars, thereby making good a serious omission character- 
ising the ]irevious form of the Bill. 

Drawings and Calculations, — Sub-section (31) makes demands which were 
the cause of some opposition on the part of engineers, but we think the Parlia- 
mentary Committee w^ere right in upholding the requirement that notices served 
on the district surveyor under Section (145) o( the London Building .A.ct, 1894, 
should be accompanied by detailed drawings and calculations of loads and 
stresses. It is certain that no skeleton buildmg can be designed without the 
preparation of such drawings and calculations. Consequently, the obligation 
to furnish copies cannot possibly cause any inconvenience or appreciable expense. 

Qualified civil engineers may reasonably object to submit their drawings 
and calculations for approval to district surveyors, who, if merely architects, 
are not in a position to pronounce judgment personally, and so will be com- 
pelled to take the advice of engineermg assistants. \\'e quite sympathise with 



s 



t.N(.INt.ERlN»i — J 



SKELETON CONSTRUCTION. 



the view tliat an eminent civil engineer would be placed in an undignified 
position if called upon to submit to the dictation of an unknown assistant 
engineer in the employ of a district surveyor. Still, we are compelled to recog- 
nise the point that the safeguards embodied in this sub-section are not directed 
against eminent engineers and architects with adequate engineering training. 
but are intended to obviate possible errors on the part of designers who may 
adopt skeleton construction without jirevious experience in that special branch 
of work. The position would be more satisfactory if all district surveyors were 
doubly qualified as engineers and architects, an ideal which will probably be 
realised in the long run. 

Finally, although the regulations embodied in Part IV'. of the new Act are 
not entirely free from points capable of further improvement, it must be admitted 
that their general purport is good, and that a great obstacle in the way of scientific 
building construction has been definitely removed. 

We cannot conclude this article without expressing our great satisfaction 
in noting that the County Council have taken the wise course of rectifying sundry 
important defects in the text as approved by the House of Commons Committee. 
This is an additional proof of the earnest desire evidenced by Mr. W. E. Riley to 
make the new regulations as perfect as possible, and for which he deserves the grati- 
tude of engineers, architects, contractors, and the public generally. 



We ha\e received the following conmiunication on the subject of the new 
amenilments for steel frame structures from Mr. S. Bylander, the well-known 
steel designer associated with Messrs. Waring & White, Ltd., and we are adding 
this as an appendix to the foregoing article on "Skeleton Construction and the 
Amended London Building Act." 

APPENDIX. 

.\ c.RK.M- advance in the ;Kio|)tion of .steol frame fi.>r buildint,"^-; in I.undon may be 
ex|x.'cted, since the new .\cl jxTmits 14-in. thicl': walls for the entire height of a buildini; 
.supported on steelwork. (In fact, a cj-in. wall is allowed for the topmost 20 ft.) 

The advantage as to econom\' is, ho\\e\'er, not so great as might have been 
expected, as the minimum thickness of walls facing streets is practically limited to 
iS in. on account of requirements of the architectural design. 

Where only plain brick walls are required, such as for area walls in the centre of 
a building, the advantage is more clearly marked, both as to economy and simplicity 
in construction. For instance, in a building having five storeys above the first floor, 
the walls, according to the old .\ct, had to t)e 2 ft. 3 in. between the first and second 
floors, although supported on heavy girders at every floor level. The new .Act permits 
14-in. walls for a similar building, much lighter girders being required. 

What is of far greater importance, however, is the fact that the new .-\ct will 
encourage better construction on lines of good engineering, and thus provide stronger 
buildings for less, or at least the same, cost. 

-Architects and engineers will have definite data to work from, and must design 
the steelwork carefully and with due regard to safe loads and stresses, and while i:>er- 
mitting more freedom in design, a more rational and economical form of construction 
can be adopted. The Act specifies the maximum stresses which may be used, while, 

'3 



LONDON BUILDING ACT. 



CQNCRETEJ 





Section of " Morning Post " Blilding Lon 



il 



SKHLHTON CONSTRUCTIOS' . 



01 course', ihc ouiRT will i(c|uiro as high stresses as may be permitted for the purpose 
of Urepint; I he lusi <lo\\ii. ICxtremes are therefore |)revented from bolli sides. 

A conip.irisin ol the constnuiion required in eoiifuDiiity with the old and the 
new .\c\ e^in be seen in I'igs. i and j resiK'Clivclv. 

/•'/I,'. I is a section of the front exterior wall ol the Monuiif; I'ost building in the 
Strand, London, as built in accordance with the old Act, and t-'ii^. 2 shows how the walls 
eoidd now be built according to the new Act of igoq. 

The need of revision of the old Act is very evident from the fact that a building 
surrounded by streets on all sides and having no interior party walls could most 
probably be built without any exterior walls up to lirst lloor, and the thick walls 
supported on cast-iron cohnnns of very small diameter (to suit shop windows) and 
extending down to basement tlixir ; thus no reliable lateral rigidity would be assure<l. 

The new Act requires the structure to be rigid to withstand lateral pressure. 

Referring to Fii;. i, it will fx' seen that the thickness of piers at ground lloor is 
5 ft. This is do)ie entirely for the purpose of obt.iining deep reveals for ground floor 
w indows. 

.'\t the ground, lirsi, second, (bird ;\n<l fourth floors the thickness of walls is 3 ft., 

2 ft. 3 in., I ft. 10^ in., I ft. (1 in., 1 ft. i\ in. respectively. They could now be built 
much thinner in conforniity uiih the new .\cl, as shown in Fit;. 2. 

.\s tlie old .\ct s]X'cilies that the roof for a building of the warehou.se class must not 
make an angle with the horizontal of more than 47 degs. a mansard roof could therefore 
not be built without adopting the method shown for roof lietween fourth and fifth floors, 
namely, by building a wall of regulated thickness and filling up with concrete to form 
the mansard roof. The roof is thus considered to start at the lifth floor. 

This construction is, of course, irrational, but the London County Council woidd 
now .appear to li.ive [xiwer to modify the ; equirenients in similar cases, as shown in 

It m.iy lie .idde*! that the Mmiiiit}; Post is an oilier building, and not ;i warehouse, 
save the basement, where the printing machines are placed. 

It is hope<l tb.it the London Coimty Council will soon issue regulations for the use 
of reinforced concrete similar to those now conl;iini'<l in the new .\ct for structural steel. 



REINFORCED CONCRETE. 



[CQNCRETH 




o \ REINFORCED CONCRETE 
' FOOTBALL STAND AT 
BRADFORD. 



The structure that nue are describing is one of considerable technical interest, and is an 
excellent example of the practical and economical application of reinforced concrete for the 
many structures necessary in connection 'with our 'various sports — notably, race stands, 
football and cricket stands. —ED. 



A NOTABLE example of reinforced concrete construction is to be seen in tlie large football 
stand of which we show illustrations, and which was recently erected for the Bradford 
City Football Club, Ltd., at Midland Road, Bradford. 

The whole of the new stand has been constructed in reinforced concrete, with the 
exception of the covering roof. 

In plan the stand has a length of 330 ft. and a breadth of 27 ft. 4 in. at its wider 
end, diminishing uniformly to 13 ft. 4 in. at the narrower end. 

The stand platform is partly inclined and partly horizontal, the horizontal portion 
forming a distributing passage and the inclined portion being stepped with concrete 
degrees to enable the crowd to see the field of play. 

The area of the inclined flooring and passage supported is 6,948 sq. ft., and the 
upper level of the flooring is 34 ft. above street level. 

The columns are of varying sections and rise to a total height of 40 ft. above 
street level for the support of the iron principals of the roof. The reinforced concrete 
decking slab has an effective depth of 4 in., and is reinforced by a grillage of bars 
over its entire area. The secondary beams run transversely, and they are therefore 
all inclined to the horizontal. 

In order to provide for the change of plane in the flooring, i.e., from inclined to 
horizontal, the secondary beams were formed of special design to admit of this in 
the back row, and consequently the depth varies in the length of the beam, as can be 
seen from our illustrations. We have called si>ecial attention to this point, as it affords 
a demonstration of the exceptional adaptability of reinforced concrete construction. 

The main beams and lintels run longitudinally, and have a section 12 in. in 
breadth by 21 in. depth, measured on the vertical axis of the beam. These beams have 
a clear span of 26 ft. 3 in., and the columns are at 27 ft. b in. centres. 

The concrete degrees were formed by being laid solid on the reinforced concrete 
decking after the latter had set. These degrees are bonded to the reinforced concrete 
decking slab by means of frequent wire ties, so as to ensure an absolute and definite 
connection, -and the horizontal surfaces of the degrees were finished in granolithic. 

The calculations for the design of the structural details of this work were based 



16 



^. £N(ilNEERINti — 1 



liRADFORD FOOTBALL CLUB. 




J— .9 ri-L-^, 



17 



REINFORCED CONCRETE. 



ICDNC RETEJ 




i8 



t.N<ilNt.l.PINIi — J 



BRADFOUI) FOOT HA [J. CLUB. 




REINFORCED CONCRETE. 



[OONQJETEI 



g 




























\ 




/ 




^ 


/ 





























-l- — L 







5-_c -Li , J^-,J^o,4 



r" 

2 


/ 


1; 


> 


[ 
i 


i — 


of 
D 




! > 


.1 

m 

< 

1 




% 






J 


-« 


s 




i < 


i 


-U 


-«— 




^ ^ 1 






■Y'^ 


_Ei-*i— Zi 


+-n-n 












< ..: 
J. ^ 


























1 




z 


: 


\ : 






/ 




\| 










t 

















r y.c&N.MDUl-riONAl.l 
L'^ l-N(.INt-l:tflN». ~J 



BRADFORD FOOTBALL CLUB. 



on tin- sii|>ciii>,id aiisinj;- from a donst-ly packed crowd, plus the self wt-ij^lu of the 
striicUirc and ol the concrete deforces, with an ample co-efllcient of safely. 

Atlt'iition may be directed to the extremely elVicient desii,Mi and disposition of the 
reinforcement fcr tlie reinfurceii concrete beams, ensuring; tlie mtiximiim of stiffness 
and rij,nilily. The dcsif,'tiers have introduced a number of luirizoiil.il, lonjjfitudinal, and 
tr.uisverse struts nt different levels for bracinfj;- the pillars loyc-ther. .Ml these struts 
li.ive been desijjned as " symmetric " beams. 

It will be observed that no di.-is^onal struts h.ive been inlroduced, this beinsj avoided 
by the pillars beins.; desitfiied of sufficient strenj^'lh to meet ;iny l.-iteral stresses, which 
iiia\' be developed in their free leii<>lhs. in this w.av not onlv has ftill benefit been 




Detjils of Beams and Brackets. 



taken of the economic advantatjes of reinforced concrete construction, but 
may be possible to utilise the under portion of the st;ind at some future dtite. 

The back of the stand havini^- been left entirely open underneath for the 
affords a most strikinij example of reinforced concrete open framework. 

The contr.-ictors responsible for the execution of the work were Messrs 
Ellis &■ Sons, Ltd., of Leicester, and the steel reinforcement used was supp 
The Trussed Concrete Steel Co., Ltd., of London. 

We reproduce from the workinji drawing's, kindly lent us for this pur| 
Messrs. F. .\. Macdon.ild & r.irtners, detai's sbuwint;- the structurtd membc 
method of reinforcement. 

The work was carried out to the plans of the .-irchiteci, Mr. .\r 
Leiich, .M.I.Mech.E. 



■ . John 
lied bv 



ose by 
rs and 



REINFORCED CONCRETE. 



ICDNCBETEJ 



The cement uijed \vas the " Fcrrocrete " brnncl, supplied by The Associated 
Portland Cement Manufacturers lnjoo), i,ld. 




The-detail designs and dra\viii_t,'s fur the reinforced cuiicreu- woric from which 
the worlc was executed were supplied by Messrs. F. A. Macdonald & Partners, consultinsj" 
engineers, 135 Wellington Street, Glasgow. 



^ENGINU PINd ~J 



CEMENT IN SHAWATER. 




THE INFLUENCE OF SEA^ 

WATER ON CEMENT AND 

CONCRETE. 



Apjrt from the eicelUnt pjr^-rs /^'t-it-'i/t-J on the occasion of the meeting of the 
International Commission on Reinforced Concrete at Copenhagen a number of ■very'-vatuable 
pamphlets vyere Jistributed, among which -were tlvo on the problem of the influence of sea- 
ivater on cement and concrete luhich call for special attention. The Danish paper on the 
sublecl "mas by Mr. A. Paulsen and the German report v/as issued by the Association of 
German Portland Cement Manufacturers, from -which summaries have been prepared for us 
by Mr. Cecil H. Desch, D.Sc, and tue are indebted to the firm of Julius Springer, Berlin, 
for our illustrations. — ED. 



TiiK qiu'slion of thi- chaii>^fs undcrt^one by cciiu-nt mortars and concretes in contact 
witli sea-water, of such enormous importance in connection with the construction of 
(liK-l<s, harbours, and coast protection works, has been investisfated by many worliers, 
prominent among whom is I^ Chatelier, without leading to entirely conclusive results. 
Systematic tests of this kind necessitate considerable orgamisation, as it is not 
siitlicient to immerse laboratory specimens in vessels containing sea-water, but the 
actual conditions prevailing in coast constructions — rise and fall of tides, exposure to 
air and frosts, variations in temperature, etc. — must also be taken into account. The 
results of two verv extensive and systematic series of tests have just been published 
almost sinudlanc ously, willi the elTect of adding materially to our knowledge. 

REPORTS OF TESTS. 

The first series is due to the initiative of the Scandinavian Portand Cement Manu- 
facturers, witli the co-operation of the harbour authorities. The report, drawn up bv 
the Chairman of the Committee, Mr. .'\. Poulsen, was presented to the International 
.\sscx;iation for Testing Materials at its recent Congress in Copenhagen. The second 
series forms a part of the extensive researches in connection with cement undertaken 
by the great German testing station at Gross-Lichterfeld, near Berlin, and is dr;iun 
up by Prof. Gary and .Mr. C. Schneider, and published in the Bulletin of that institution. 
Both series of tests have been conducted over a period of ten years. The Scandinavian 
results are perhaps the more interesting of the two in respect to the light they throw- 
on the conditions prevailing in practice, although the climatic conditions are rather 
more severe than are usually encountered in this country. 

SCANDINAVIAN TESTS. 

The Scandinavian scheme emliraced the testing of cubes of mortar, and of concrete 
blocks prepared with the same mortar, over periods extending to 20 years, of which 
ten have now expired. Four Portland cements were selected for the mortars, one each 
coming from Norway, .Sweden, Denmark, and England. The hydraulic lime 
of Teil, which enjoys a certain reputation for marine work on the Mediterranean coasts, 
was also included in the series. For the concrete blocks the same cements were at first 
used, with the subsequent addition of six more Scandinavian Portland cements, and 
of mixtures of cement with Rhenish trass, Danish infusorial earth, Santorin earth, 
puzzolana, slag cement, etc. The sand and ballast were taken from the beach on the 
west coast of Jutland, and consisted of practically pure quartz and flint. 

D 2 ' 23 



CEMENT /.V SEA-WATER. [CONCBETEJ 

Test.'ag Cement Cubes. — The cement cubes were placed in sea water at Esbjerg, 
the most souiherlv North Sea harbour in Denmarlc. and at \'ardo in the Arctic Ocean. 
At each of these places two similar sets were placed, one between tide-marks, so as to 
be alternately covered and exposed twice in each 24 hours, the other at such a depth 
as to remain submerged even at low tide. A fifth set was placed below tide-level in the 
harbour of Deserhamn on the Baltic, where the water has only one-seventh the 
salinity of that of the North Sea. From each cement four cubes were prepared with 
sand in the proportion i : 3, four of i ; 2, four of i : i, and one of neat cement, or 13 in 
all. This scheme being- repeated with each of the five cements gives 65 blocks, to 
which must be added 12 cubes prepared with one of the cements and coast sand instead 
of the usual " normal sand," making 77 cubes as the total of each set. As the tests 
were to be carried out in the five different situations named above, and the cubes were 
to be crushed at intervals of 3 months, 6 months, i, 2, 4, 6, 10, 15 and 20 years, this 
involved the making of 77x5x9 = 3,465 test cubes. The results obtained, from cubes 
e.\posed for less than a year proved to be irregular and of little value, and in any 
future scheme of the same kind it would be well to omit the short-period tests, and to 
provide for the extensiim of the long-period test to 30 years. 

Testing Concrete Blocks.— Over 100 concrete blocks, mostly 2 ft. 4 in. x 2 ft. 
X 4 ft. 8 in., but occasionally i>f half that size, have been prepared, and built u]) to form 
a grovne at Thvborcin, on the west coast of Jutland. Compression tests on the blocks 
after exposure being impracticable, the testing was confined to a simple ins]X'Ction of 
the blocks after determined intervals and the occasional chemical analysis of fragments. 
Each block was furnished with a galvanised iron lifting bolt and number plate, and in 
addition to this coloured beads and small pieces of broken coloured glass were in- 
corporated into the concrete during mixing, the colour of the beads indicating the 
proportions in the mixture, and the colour of the glass the kind of cement used. By 
this means even a broken fragment of a block could be identified. The blocks w>re 
mi.xed by hand, and Uei)t moist for four weeks before putting in place. 

Results. — In considering the results, it is necessary to bear in mind the conditions 
of the test. The cubes and blocks placed between tide-marks were exposed at each 
ebb to the influence of the sun, and in winter of frost, the latter factor being especially 
prominent at \"ardo. The disintegrating effect of such alternations of saturation, 
drying, and freezing is very great, and these are the conditions to which breakwaters, 
grovnes, and marine embankments are continually exposed, particularly in northern 
latitudes. To these influences must be added, in many inst.-mces, the abrasive action 
of drifting sand. 

To take the mortar tests first, the results showed very little diflerence between 
the three Scandinavian cements. The solitary English Portland cement used was un- 
fortunately not a good specimen, as it disintegrated completely under the boiling test, 
and gave throughout lower crushing results than the other cements. There was very 
little difference between mortars made with normal sand and with shore sand. The 
effect of repeated freezing is disastrous, the only specimens capable of resisting the 
exposure between tide-marks at \'ard6 being the richest (i : i) Portland cement 
mortars. The Teil hydraulic lime proved to be, in its strongest mixtures, only equal 
to the weakest cement mortars, and was particularly weak when exposed to frost. 
That hydraulic lime stands well in the Mediterranean is to be attributed to the absence 
of frost and .-ilso of tidal rise and fall. 

The chemical action of sea-water on cement appxears to be less marked than has 
been generally supposed. .-X good cement shows comparatively little chemical change 
after 10 years' exposure, beyond an increase in the proportion of chlorides. Neither 
the magnesia nor the sulphates show- any marked increase. On the other hand, the 
poonr mixtures of hydraulic lime show a great loss of lime and replacement by 

H 



l/.tON.VItlK-liONAl.l 
L'^ t:N(WNt,t.RlNl. — j 



ci-:mhst in sea-\vati-:r. 



K.KncMa :,n,l .ulphat.s. Mud. sce.ns ... ,lc|x.,ul on .h.- n.,np:,c.n.ss of the ,„or.:.r; 
hou.u.^^hy d.nsc- m.x.urc. only allows dilfusion .o lake place- so slowlv that the cIT • 
■ s a most nc.«l,«,ble after several years. A loose nu>r.ar, by nliowi„« salts 
penetrate to the interior of the mass, is rapidly disintcjrrale-l. 

Tiirninf' now lo 
ihe concreic hlocUs, *•■ ■ ^ 

tlie arrangement of 
these in the }»royne is 
seen in /'Vi,'. i. A few- 
blocks were disUxl^eil 
l)y storms and so 
tlamajjed, bill Ihis 
a c c i d e n I ilid not 
maler.'ally allocl Ihe 
results. The first 

lesson of the tests is, 
that ;i stilViciently rich 
mortar should alw.-ivs 
be used, as bh>cks 
m.ide with ,i i : ^ 
mortar almost alw.-iys 
disintegrated, whilst 
the I : 2 niorlar is 
StilViciently strong, at 
le.ist as far as can be 
itidged by the lo years' 
tests. .\ny i,f(xxl Port- 
land cement appe.irs 
to be suitable, the 
rliemical com|)osilion 
undergoing I i I t 1 ,■ 
change bcyoiul .in 
increase in the m.ig- 
nesia and sulphates, 
■riir bl,*-ks made with 
hxdraulic lime sulTered 
badly. .\ nii.xture of 
sands of different fine- 
ness is advantageous, 
although, rather 
curiously, the best 
results were not given 
b\ the closest mix- 
tures, but by concretes 
containing an excess 
of very fine sand. The 
addition of very finelv 
ground trass or sand to the cement save better results in some cases, whilst other 
mixtures, especially those containing infusorial earth, gave verv inferior results 

rwo special forms of blocks were also tested, namelv, those made bv Kinipple's 
method, by which pure cement and water is forced down into a mould containins^ the 
aggregate, without any sand, immersed in the sea, and hollow reinforced M'onier 




CEMENT IX SEA -WATER. 



[CONCRETE] 





haao 

z6 



J, CONM WIK-nONAl.l 
'■^ t.N(.INI:.I.KtM(. —J 



CHMBNT IN SHA-WATER. 




SP. 



« 4 I g 










ffW^ 



l< I' l.l»M^^ 



CEMENT IN SEA- WATER. [CONCRETE] 

blocks Both stood the test well, but cost and resistance to the impact of drill timber, 
etc., are factors which have to be talvcn into accou)it in determinini,' their value. 
GERMAN TESTS. 

The (lermaii tests were conducted at the laboratory of the .Association of German 
Portland Cement Manufacturers at Westerland, which was reconstructed and enlarged 
for the purpose. The concrete and mortar cubes and the tensile test pieces were 
immer.sed in two tanks, containint; fresh and salt water respectively. The large 
concrete blocks for exposure to the tides were allowed to remain in moist sand for three 
months in some cases and one year in others before transferring to their places in the 
groyne, where they were covered and uncovered at each rise and fall of the tide. .\s 
in the Scandinavian tests, each block was provided with a galvanised iron lifting bolt. 

Two German Portland cements were used in the final experiments, one of wliich 
was richer in lime than the other. 'I'he .addition of finely-ground trass was also 
included in the exixjriments, as well as thr use of mortars composed of lin-.e and trass. 
.\11 mortars and concretes were mixed in a machine, and rammed in moulds, and 
comparative tests showed that hand mixing, at least in the case of mixtures of lime 
and trass, gave results distinctly inferior to those obtained by machine mixing. 

The mortars richest in cement in all cases resisted exposure to sea-water best. As 
regards trass, its addition to the cement lowers the initial strength, but causes 
hardening to take place more rapidly, so that mortars containing trass gain rapidlv 
in strength when stored in fresh water, but in sea-water the action, so far as tensile 
tests are conct-rned, is the reverse, the trass mixtures starting well, and then falling off 
in quality. It is not possible to decide this point quite definitely until more of the 
long-period tests have been completed. The two cements used were very unequally 
affected bv the addition of trass. Throughout the tests cement A, containing 65-9 per 
cent, of lime, behaved better than cement C, which contained only 62 per cent, and was 
high in alumina, but it is not certain that the difference is to be ascribed solely to the 
lime content, as tlie mode of combination of the constituents may have been different, 
and the difference in the projjortion of aluminates must have had a great effect on the 
cements. 

The influence of the various factors appears more clearly in the behaviour of the 
concrete blocks in the groyne than in that of the smaller blocks in the tanks. Nearly 
all the blocks made with cement C developed cracks, whilst those made from cement A 
resisted well, esi>ecially when made with the richer mortars. Poor mortars, but not 
rich, were improved bv the addition of trass. Blocks allowed to harden for a year in 
moist sand invariably resisted better than blocks only allowed to harden for three 
months. Mixtures of trass and lime, if rich in lime, became abraded by the action of 
drifting s;md, but did not disintegrate, whilst poor mixtures scaled off. Lime in 
powder gave slightly better results than wlien ailded to the mixture as a cream. 

General Appearance of Blocks. — The general ap<|)earance of the small blocks 
after exposure to sea-water is seen in i•/,i;.^. 2 and 3, which represent the following 
mixtures : 

No. I in Fi^t;. 2. — Compression blocks, i cement : 4 normal sand, after 5 years. 

No. 2 in Fii;. 2. — Compression blocks, 55 cement : _|5 fine sand : 400 normal sand, 
after 6 years. 

No. 3 in Fii;. 2. — The middle blocks of Fig. 3, removed from their frames. 

No. 4 in Fig. 3. — The same mixture as in Figs. 3 and 4, but with a somewhat 
different cement, after 5 years. 

No. 5 in Fig. 3. — The same series, after 6 years. 

No. 6 in Fig. 3. — The tensile test-pieces of the same series, after 6 years. 
The size of the mortar cubes for compression was 50 sq. cm. surface (approximately 
3 in. side). The " fine sand " and trass were ground to pass a sieve with 900 meshes 
28 



[^I'^^r^^a:'.;^^] CI-MHNT IN SI-A-WAT/^R. 

|XT stj. cm. (7_, per liiicar inclil, aiul wcio tlionmijlily incorijoratcd with the ccnu'iil l>v 
j^rindiiij.; before niixiiii;;. The Cdiicn'Ie cubes Uir compression were of 12 in. side. 

.\ uord may be s.iid .is to (lie woiKJen rr.imes used in Iioltlini;^ the cubes in pl.-ice 
during the sea-water tests. The (ierman lists, bcinj^ conducted in .a tanlv into which 
tlie sea-water was pum|x'd, did not call for any special arranf^ement, and the simple 
frames shown in l'i,i;s. 2-\ seem to have proved quite satisfactory. In the .Scandinavian 
experinie'nts, however, the i)resence of V'orci/o and other wood-borinj^ Crustacea in the 
liarbours of Ksbjerij and \ardo made special precautions necessary. Dc.il frames 
could only be used for the shortest period tests. For others, oak frames, strongly 
bolted toj^ether, 12 ft. <S in. loni,^, each capable of holding So cubes, were used. .\t 
Vardo, even these were attacked, and it was found necessary to construct the cases of 
-Vustralian jjfreenhearl, which is pr;ic;icdly luialt.icked by crust.ace.a. 
CONCLUSIONS. 
As f.ir .as it is possible to dr.iw di'linile conclusions .at present, the followint,"^ may 
be said to be the principal results of the two series of experiments : 

I.- (icjod Portland cements, such as are now on the luiropean market, are 
very resistant to the action of sea-water. .\ m.irked difference in the behaviour 
of cements of sli-^htly dilTerent com|K)sition has not been found, except that a hig'h 
proportion of aluminates tends to cause disintegration. 

2. — In a dense mortar, the chemical action is confined to an outer Layer of 
sm.ill depth, further action beini; checked by the slowness of diffusion. .\ ])orous 
mortar, by admittini^ s.alt water to the interior, is apt to crack by exp.insion owinij 
to cliemical chan}j;e. 

3. — The main a{.jency in the destruction of mortar and concrete in m.irine 
embankments, harbour works, <;rovnes, etc., is not chemical action, but the alter- 
nations of saturation, dryinij in the sun, freezinjj, etc., due to the alternate 
exposure and covering by the rise and fall of the tide. Destruction takes place 
sometimes by cracking, sometimes by scalinjj;', the latter effect being produced 
especiallv by frost. 

4.--'riu' denser the mort.ir the better (1 cement: 3 srmd is too p(H>r). .\n 
admixture of fine sand with the ordin.iry s;md increases the closeness of the mixture. 
A well-graded aggregate would be advantageous for the same reason. 

5. — The .addition of finely-ground silica or trass to the cement before mixing 
is pos.sibly advantageous in the case of weaker mortars. It is very doubtful 
whether anythini;- is gained by adding trass to the richer mortars. 

6. — Hydr.uilic lime mixed with trass, etc., whilst of some value, where a 
cheap material i- ni.|uirrd. in ihc mild clim;ite and absence of tide of the Mediter- 
rane.an, is iucipablc of w illiNi.irulinj^ the conditions of co.ast work in northern 
latitudes. 

7. — The destructive action of the sea beiny; m.iinly physical and mech.anical, 
and not chemical, tests by mere immersion in still se;i-\vater are of very little 
value in determining the behaviour of concrete in m.irine engineering works. .\ 
mixture which disintegr.ites under this test is cert.ainly useless, but a mixture 
which passes the test mav disinte5.;rate under the more stringent conditions of 
practical use. 

8. — .-\s long a periotl as is practicable should be allowed for the hardening- of 
concrete blocks before placing in the sea. The German recommendation of one 
year in moist sand before setting in place is probablv impracticable in most places, 
but shoidd be approached as nearly as ]X>ssible. 

c). — The behaviour of test-specimens for the first 12 months is very irregular, 
and definite conclusions can only be drawn from the results of long-period tests. 
Both of the reports contain very full tables of crushing and tensile tests, and a 
complete record i>f the aiii.iearince of each concrete block at stated intervals. 

.-9 



THE CONCRETE INSTITUTE. 



ICQNCBETEl 







THE CONCRETE INSTITUTE 

PROPOSED STANDARD NOTATION FOR 

CALCULATIONS IN REINFORCED 

CONCRETE WORK. 



cotton on the proposed standard algebraical notation for the calculation of 
reinforced concrete vjork transmitted to us by the Concrete Institute iS, in our opinion^ one 
of the utmost importance to the members of the technical professions in English-speaking 
coantrieSp and *we thus publish the communication 'With its enclosure in full, and shall te 
pleased togiiie later on any comments we receive on the subject.— ED. 



The Science Committee of the Concrete Institute, which has been doing such 
excellent work under the chairmanship of Mr. William Dunn, F.R.I.B.A.. Mr. 
F. E. Wentworth-Sheilds, M.Inst.C.E., acting as Hon. Secretary, is mainly 
responsible for the communication we publish below on the question of a standard 
algebraical notation for calculations in reinforced concrete work. 

The Institute, and its Science Committee in particular, are to be congratu- 
lated on this painstaking piece of work, in which, we believe, Mr. E. Fiander 
Etchells, F.Phys.Soc, M.Math.A., has been an active and enthusiastic pioneer 
If the Institute in this early period of its life can produce contributions to our 
national and even international co-ordination of technical problems, it is cer- 
tainly doing praiseworthy work, and is rapidly proving the utility of its existence. 

The communication we have received reads as follows : — 

I Waterluo Place, Pall Mall, 

London, S.W. 

i8th December, 1909. 

Sir, — I am desired by tbe Cuuncil of the Concrete Institute to forward you copies 
of a proposed standard notation for formula? employed in reinforced concrete work. 

In 1909 the Council, havinsj reg^ard to the confusion arising' from the many various 
symbols used for the same quantit\- by scientific writers and the advantages of an 
agreement on a standard not;ition, referred the matter to its Science Committee. This 
Committee was later requested to consider the pro]>osaI for a standard notation received 
Iroin the International Commission on Reinforced Concrete (founded by the Inter- 
national Association for Testing Materials). 

The Science Committee resolved : — 

1. That the " Three-alphabet " system adopted bv the International Commission, 
consisting of ca[;ita! Roman letters, small Roman letters, and small Greek letters, be 
approved. 

2. That the principle of the initial letter, i.e., the use of initials or distinctive self- 
explanatory letters of the governini;" words that were employed as a general rule for 
abbreviations, should be adopted. 

3. That the desired uniform mathematicil notation for the most important magni- 
tudes occurring in the specifications and statical computations should be drawn up, 
so as to be in harmony as far as possible with the l.-mj.juage in which such specifications 
were written or made. 

-A Sub-Committee consisting of Professor .Adams, Mr. W. Dunn, Mr. E. F. 
Etchells, Mr. J. E. Franck, and Mr. C. ¥. Marsh was then appointed to prepare a 
draft report, which was considered bv the whole Committee, and after some inodifica- 
tiun was eveniually adopted. 

30 



I 1. CON<fTBnCTlCK*fl 



ST A SDA RD NOT A TION. 



fopiis i)f this drali report were sent to Professor Meljin, and were considered by 
a Coinniiltee of the Internalional Conniiission on Reinforced Concrete at Coix^nhajjen 
in September o{ tliis year. 

It was found tlial the princi|)le of the initial letter formed an obstacle to aj^'reement 
with continental nations. 

For instance, in En}.;land and .\nierica 1/ would l>e used as a contraction for depth 
and /> as .1 contraction for breadth, but the contr.ictions of the French words " hauteur " 
.uid " l.irf^eur " would ji'ive us li .and /. .\^',iin, i>n the Continent, Greek sm.alls are 
iimhI for intensity of stresses. 

Tlie American and Ivnjjlish delegates to CoiKadia^en (Professor Talbot, of 
Illinois, C.S.A., ,iiid Mr. William Dunti, Ch.airman of the Science Committee of the 
Concrete Institute) were of the opinion set out in the report, viz. :- That it would be 
dillicult to induce the En^lish-s]X^aUini^ peoples to adopt the Continental practice in 
respect of the use of Greek letters for tensile, com|)ressive, and shearing stresses. 

It was felt that such a general agreement as is embixiieil in the resolutions of the 
Science Committee previously dr;ifted is all which could be hojx-d for at present, and 
that the Knglish-s|x\aking [x.'oples should endeavour to agree on a standard not.ition 
for their own use, based e>n the abbreviation of English words. 

Copies of these prO|X>saIs of the Concrete Institute have been sent to the British 
■and .\merican Societies concerned. 

Voii will, 1 :im sure, realise th.it if sucli a list could be adopted by the .American 
and I'jitili-.h nation-, it woidd be .in immense boon to both. 
I am, sir, yours very truly, 

.\uTiHK E. Collins, Hon. Secretary. 
I he Editor. Com liKTK \m5 Consikii tionai. Esc.im-.kkino. 



[DRAFT copy 
DRAFT REPORT OF THE SCIENCE STANDING COMMITTEE. 

I'KINCIfI.ES .\l>OI'TKD. , 

Algebraical notation in engineering formuke should l>e simply a species of short- 
lianil in which une letter stands for a word or phr.ase. 

This species of shorthand should have a logical basis, should be self-explanatory, 
and should not tax the memory. 

The simplest and most natural system is to abbreviate the significant words to 
their fullest extent. For exanii)le, successive abbreviation of longhand would give us 
in tLirn such, forms as diameter, ilium, dia, and finally d. 

This principle of the initial letter, or distinctive self-explanatory letters, has been 
ido])li-<l with great success in chemistry and in ordinary daily life, in titles and the 
names of institutions, etc. 

ll ma\ be urged that by the adoption of successive abbreviation confusion may 
arise, but tin- risk of confusion is lessened by classing our quantities into definite 
groups and taking advantage of the differences between ca[)ital and small letters. 

The risk of confusion is reduced to a minimum by the .idopiion of what is known 
as the three-alphabet system. 

rilKKi:-All'lIAHKT SVSTR.M Ol-' NoiATlOS AlWPll.D lO Till-. Kscatslt l.ANC.l .\r.F.. 



Linci! dimensions (leni; 


ths 


and 


.\reas .and volumes 


distances, etc.) 






Moments 


Intensitv of forces 






Total forces 


lntensit\- of loads 






Total loads 


Intensity of stresses 






Total stresses 
Angles 


Constants, etc. 






Constants, etc. 



C;i-<tk Sin 


.11, 


— 




.\ngles 




Constants 


etc. 



THE CONCRETE INSTITUTE. [CONCRETE] 

It should be borne in mind thai this table is prnctically in accord with existing 
Enyh.-li and American practice, except that the vagaries and inconsistencies have been 
elimitiiited as far as possible. 

For some years now there has been .an imonscious driftin.y; towards some such 
classilication as that now definitelv formul.ited. 

The consistent adoption of the three-.dpliabet sysleni and the initial letter system 
would lift the problem of a standard notation out of the realm of ix-rson.al bi.a- .and 
place it on a broader basis. 

.\ttention is invited to one of the threat .advantaijes brousht about by the frank 
acceptance of the three-aphabet system ; for instance, in dealing with bending moment 
the fact that it is a moment is sulTiciently indicated Ijy the use of capitals, so that we 
can have the two single symbols — 

B = Bending moment of the eMein.d forces. 
R = Resistance momcnl of the internal stresses. 
Now, if ue use M„ for Bendiny -noment we eanmit e.isily with a simple praciictiJ 
s\-mbol discriminate between : 

1. Beirding- moment a .any disi.anee X from the left supijort. 

2. Bending moment al the centre ol .1 ln'am. 

V Bending moment at ihe rni] uf a beam with fixed ends. 

If, howcxer, wt- use B to represrnt bi-nding momt-nts, we get the following brief, 
simple, antl sflj-cxl'laiiattiry reductions : 

B = .Maximum bending'' moment on .1 be.ini. 

Bx = Bending moment at the dist.ance X from the left support. 

B(- = Bending moment at the centre of a be.im. 

Bj.= Bending moment at the end of .1 beam with fixed ends. 

Moreover, if B be used instead of the more usual B.M or M^ we get the following 
consistent series : 

B= Bending moments on beams. 
1 = Inertia moments. 
.M = Moments in g'eneral (or Mass moments in dealing with dMi.aniical problems). 
= Overturning moment. 
S = Stabilit} moment. 

N.\TIRAL Ll.MIT.niO.N Ol- .Sr.ANDARmSATlON. 

It has been suggested that a Universal .Standard Notation for all branches of 
engineering and for all languages should be adopted, but this is impossible for the 
following reasons : Confining ourselves to the Latin and Greek alphabets, we have a 
total of about 100 letters, but we must deduct about i^ of these on account of the risk 
of confusion. We have thus 67 symbols left. 

Now, in the various branches of engineering there are m;my hundreds of terms 
embodied in equations in some form or other and onlv (57 symbols to represent them. 

It should be obvious, therefore, that in the various branches of engineering the 
same .symbols must have different meanings. 

.Again, an international system of notation wcnild not ajjpear suitable for dailv 
national use, for in so far as it were self-explanatory to the English-speaking peoples, 
so far would it be a matter of memory to the other nations, and vice versA. 

.\n artificial .and arbitrary notation devised by savants for international use could 
not hope to obtain the unanimous support of any nation, for a polvglot notation would 
be more of a hindrance than a help to the majoritv in anv countrv. 

It is suggested that notation should follow the language of the text, i.e., that 
French not.ation should be an abbreviation of French words, and (ierman notation of 
German words. The three-alphabet system could, of course, be adopted bv all nations, 
though the actual symbols used would be different. 

3» 



n^^^Sggii^ • STAXDARD XOTATION. 

I.KC.IKII.ITY Ol- N'orATlON. 

If the small Roman Idlers of the iirilinary letterpress on any printed page 
determine the size of the subscript letters, such as .\q or /^, etc., it will follow that the 
subscript letters, beiufj from a smaller fount, mav be loo small to be easily lej.;ible. 

It is, therefore, reconuiiended th.-it .-dl our symbols be set in larj^^e type, so thai the 
subscript letters may be reasonably clear and unmistakable. 

It is also sui;-},'-ested th.at the L.atin smalls sliould be in it.-dics and the Latin 
capil.ds in uprii,'ln letters, so as to help to discriminate between c, s, "u', v and C, S, 
W, W clc. 

List oi' .Sv\tuoi.s. 

The acceptance of ihc .above broad principles will do nnieh to build up .i n.ilur.'d 
st.and.irdisation, to which all writers will fjravitate, with the .issur.mce th.at anv new 
symbol they may be compelled to introduce will be certain to win its w.iy to j,'eneral 
.ippro\-;d, provided that it is consistent with these principles. 

The attached list of symbols is not complete, but will lie found sulTicient to men. 
(he more pressinij needs, and will serve as .in illusir.Liion of the b.asic princii)les herein 
formulated. 

S\Mii()is I \i>i-riNi)i;\T Ol- I'Niis EMi't.oviai. 

The not.ition has been drafted so as to le.ave the symbols independent of the 
m.itjiiitude of the various imits. 

For example, p represents intensity of pressure, whether that pressure be measured 
in poiuids per square inch or tons |Kr squ.ire fool, or even in Uiloijranimes per square 
ci'nlimetre. 

.\s this notalion does not vary .leeonlint; to the ma,!.;nitude of the units employed, 
■.u-\i\ as every .author has his own opinion ;is to what units are most suitable for any 
t;iven case, it is necessary for authors to s])ecify in every case what units they employ, 
l-'or example, accordini^ to circumst.ances, -le mav represent — 

Weitjht per unit of Icntjlli ; weight per unit of .area; weit;ht per unit of volume. 

lu.ASlK 1 tV Ol- 11 IK \Ol-.Ml,)N. 

.\ .t;-re;it nundier of the symbols such .as those for leniifth aikl heisjht, etc. — have 
been left in i;cner.d. terms. Before usini.;' ;iny of these it will be necessarv to specifv 
deliiiiicly between what points such lent^ths or heii^hts are to be measured'. 

Ml-.TIIOH OK Pkksf.nt.\tid.\. 
It is suss'es'ed that the t.i\ on the memory would be ijreatly reduced if the author 
would fjive his notation at the bi-iiinnin.i,'- of the book or in close proxiniitv to the 
equations. 

I losl'l lAl 111; Nor.MlDN,-. 
In specifyinj; the units employed the folkiuini,^ ;d)breviations mav be used : 
Indies = nis. 
Feet = ft. 

Cubic inches = ins.-\ 
Pounds ]X^r squ.arc inch = lbs. /in.-. 
Hundred'A-eiijhts per cub. foot = c\vls. 'ft.-\ 
Tons ]X'r square foot = toiis/ft.'^. 
Etc., etc. 

I"l RIIIKK ("L.XSSnilAllON OK SVMI'.OIS. 

There are several reasons why this list of svmbols should be presented in alpha- 
betical forni without any other classification, but in using- the symbols in books it will 
probably be found more satisfactory to divide the svmbols into g-roups such as, 
symbols for pillars, for beams, rectangukir and tee-sections, etc., etc. 

They can be readily memorised if classified, but such sji'Dnping should depend 
upon the needs of the author and the reader. 



33 



THE CONCRETE INSTITUTE. 

LIST OF SYMBOLS 

(Suggested by the Scienxe Standing Co.mmitti-.i..) 

(Subject to Revision; a)id also subject to Approval by the Council of the Cone 

Institute.) 
LENGTHS, DISTANCES, INTENSITY OF LOADS, STRESSES PER LNIT 
AREA, AND CONSTANTS. 



OI 



couple, i.e., distance 
p;irallel forces of equal 
but acting- in npiiositc 



couple formed by 
and tensile lorees 



tbe 



stress 
stres 



stres 



mlensity. 
i intensitv 



Arm of an 

between t\v 

magnitude, 

directions. 

Arm of thi 

compressive 

beam. 

Breadtli. 

Brciuith of a rectangular beai 

|)arallel with neutral axis. 

Rrcaiith of the rib in a tee-beam. 

Effective brcodlh ..( the slab in 

tee-beam. 

Coniprexs 

Compress 

concrete. 

Compress 

steel. 

\\ Rki tANfai.xn Skitio.ns: 
ncptii. 

Effective depth of a beam from 
top of beam to axis of tensile re- 
inforcements. 
Total depth. 

Total depth <:i ;\ .slab in a t.-r- 
beam. 

Depth or distance of the ccntri' 
of co})ipres.',ion reinforcement 
from the compressed edge. 

In ('ii;( it.ar Sections. 
Any diameter. 
Intern.il diameter. 
Outside diameter. 
rHameter of the core of a pillar 
with lielical reinforcements. 
Piameter of a Ion i;itndinal rein- 
forcing rod of .1 i.i'llar. 
Diameter of a helical reinforcing 
rod in any compression piece. 

I^leflection of a beam. 

Eccentricity of any load. 

Fricliioi or adhesion between sur- 
faces in units of force per unit ol 

area. 

Gravity coeflicient, i.e.. the accek-r.a- 

tion due to gravity. 

Heii^ht. 

In pile work ; height from which 

the ram falls. 

Lcn^^lh. 

Effectivi- length or span of a beam 

or arcli. 

34 



k : /( 



In pilr 
Modular rati, 
tween the el 
and concrete 



igth of pile. 
/.(■., the r.atio be- 
moduli of steel 
E,;Ec. 



Stic 



In beams : distance of the neutral 
axis from the comjiressed edge of a 
beam. 

The ratio njd, i.e., the distance be- 
tween the neutral axis and the com- 
pressed edge divided by the effec- 
tive depth of a beam. 
Percentage of steel, i.e., p=ioor. 
Intensity of pressure per unit of 
length or area in any direction. 
Intensity of horizontal pressure. 
Intensity of vertical pressure. 
Intensity of tangential pressure. 
Intensity of pressure normal to any 
given surface 
Radius. 
Ratio. 

Ratio Ol area of steel to .area of 
concrete in singly reinforced beams 
(com])are />). 

Ratio of area of steel in tension to 
.ire.i of concrete in doubly reinforced 
beams. 

Ratio of area of steel in compression 
to area of concrete. 
Shearing stress intensity. 
.Shearing stress intensity on con- 
crete. 

In |)ilr work : average set or pene- 
tr.ition of the ])ile under the final 
blows. 

Tensile stress intensity. 
Tensile stress intensity on concrete. 
Tensile stress intensity on steel. 
]'ersi)ie or camber of a curve or ris:,> 
of an arch. 

Weight ]>er unit of length. 
irc/t,'/i( per unit of area. 
Weight ])er unit of volume. 
.\nv unknown quantity. 
The independent variable in any 
function. 

.\ second unkiiown quantity. 
.\jiy function of .v, such as y = .r-, 
etc. 

.\n ordinate corresponding with the 
abscissa x, i.e., the co-ordinate of x. 
.\ third unknown quantity. 



f », coN-vrmrenioNALl 

LfVENCJNt.h-BlNC> — J 



S TAN DA RD SOT A TIUX. 



.\l-;l•:\^, \()i.i MEs, MOM i:\is, total loads, toial i<)kci:s. 

AM) constants. 

N Norma! lorcc. 



A Total cruss-scctioiial area o( a 

pillar. 
A III I'ili' w iirk : cross-scclional -ir.ii 

ol \hr pilr. 
Ai. l'rn-,s-s,-ilii«i;il ,ir, 11 ul l,<iii;iliuliiial 

steel nids in a pillai'. 
All Cross-sectioiial arra ul a luliial if- 

inforcinjjf rod in a pill.ir. 
Ae liiliiivatciil area. 

('I'liis will rt-qiiirc to be s]Hcili ■- 
ally defined lor each equation in 
which it occurs.) 
Ac Area of compressive reinforceinc.il 

in beams. 
At Area of tensile reinlorci'iiu'iit in 

beams. 
As •l''i'ii of sliear reinforcement in a 

^"■iven len^tli in beams. 
B Beiidiiii; moment. 
B Maximum beitdiiit^ moment of the 

extern.-il forces or loads on a beam. 
]!^ lieiidiiii; moment at a distance .v 

from lelt .aliutmi-nt. 
l!i lieiitliot^ moment .at eeiilre of 

beam, 
l!,; Hendiiii; moment .it end of be.im. 
C Total compressive force or stress. 
C- Total compression on concrete. 
Cs Total compression on steel. 
li, Elaslic modulus of any materi.d. 
Kc Klastic nuKkilus of concrete in com- 
pression. 
Es Klostic modulus of steel. 
Y Total friction betwi'cn nn\ two sur- 
faces. ■ 
1 Inertia moment. 

1 X Inertia moment on .i\is XX. 
1^ Inertia moment on axis \'V. 
Is Inertia moment for steel. 
Ic Inertia moment for concrete, 
M .Urii)ic)i( of a force or alt;ebraic sum 

of the moments of several forces. 



:■., force normal to 
a L;iven surface or pl.ine. 

() Overliirnint; moment. 

I' I <ilal pressure on a f,Mven area. 

1' In pile work: .Actual total pressure 
or load comiiii,^ u])on the pile. 

Ft Total lanf^ential pressure. 

Px I'ressure normal to a ijiven surface. 

I'll I'ressure (horizontal ). 

K l\esistance moment of the internal 
stresses in ;i beam at ;i i^iven cross- 
section. 

R,, I.ejt reaction. 
\<K /v'(,i,Wi/ reaction. 

Ki, Ivj, K3, etc., Reactions on inter- 
mediate supports. 

Ks In I>ile work : .Safe resistance of the 
pile to further penetration. 

Ri In pile work : L'ltiniale resistance 
of ])ile to further penetration. 

S .Stattilily moment. 

S Total sliearint; force across ;i sec- 

tion. 

Sii Total horizioital shear on a t^iven 
len,i;th. 

Sv Tot.al vertical shear at anv cross- 
section, when necessary to <liscrimi- 
nate. , 

Sc: 'Total shear t.iUrn up In' concrete. 

Ss 'I'otal siiear taken u]) by steel. 

Sk Safety factor. 

Sm .'Section modulus. 

T 'Total tensile force. 

T 'Tot.il tensile siress on .1 j;ieen cross- 



<i or .\ -Vny .intile. 

fior B Any .antfle. 

y or C Any .-mt^ie. 
61 



Tc Tot.al tension on conciele, when 

necessary to discrimin.ate. 
T-, 'Tot.-il tension on steel. 
W Weight or load. 
W,; In pile work: ITc/i'/i/ of the nuii. 
W,. In pile work : Weight of the pile. 
\NGLES, CO.\S'T.\N IS. AM) M ISCELLANEOIS. 

/i Friction hhkIuIus, i.e., the ratio of 

the tantjential to the norm.d 

force. 



Inclination of a line to the hori- 
-onial plane. 

(Note the horizontal direction of 
the line in the symbol. Com- 
pare 0.) 

Moment of resistance modulus in 
the e(.|u;ition m'><'-'= Moment of 
resistance. 



'The peripheral ratio, i.e., the r.itio 

of the circumference of a circle to 

its diameter. 

^'innmiif/oii sii^n. 

Inclination of a line to the vertical 

|jlane. 

(Xoie the approximately vertic-d 

direction of the line in the symbol. 

Compare ''.) 

Perimeter of any rej.;idar or 

irreerular fitrure. 



3r ord.'r of the ."Science .'Standing Conunitlee of the Concrete Institute. 

II. KFMnxON- Dyson', Technical .Sccic/arv. 



TESTS. 



ICQNCBETEJ 




TESTS ON REINFORCED 

CONCRETE CONDUCTED 

IN GREAT BRITAIN. 

(PART IV.) 



^ 



The absence of syslcmMic testing relating io reinforced concrete has placed this countrv 
at a disad^>antage in the utilisation of this modern material for structural purposes. Ex- 
cepting only in regard to fire tests, such in'vestigations as hai'e been conducted have been 
quite spasmodic in character^ and practically al'ways of a purely private nature. 

Halving regara to the fact that the question of a series of tests being conducted in this 
country, in a systematic manner, is halving the attention of the Institution of Civil Engineers, 
the Concrete Institute, and other scientific societies, 'we are presenting particulars, as far as 
toe are able, in chronological order, of such tests as ha've been conducted in this country 
from time to time, and this may serine as a useful guide to those tvho have the arrangements 
of the tests of the future. 

The first three articles of this series appeared in our May, September and November numbers 
respectively. The folloiuing particulars of tests are noTi* presented, and further articles 
v.nll appear from time io time. — ED. 



TESTS ON THE HERBST SYSTEM. 

Load tests on three reinforced concrete hollow floors on the Herbst tubular system, constructed 
by the Armoured Tubular Flooring Co., Ltd.. of London, were conducted by the British Fire Preven- 
tion Committee on January 2qth 



and 30th. June 7th, 8th, and 27th. 
and July 17th, 1907. The con- 
struction of the test floors is shown 
in Fi^. i;. 

The general particulars of the 
tests were as follows, and the 
results are given in the table 
on page 37. 

A mechanical bond bar of corru- 
gated section ribbed across was 
embedded in each web about i in. 
above the soffit. These webs wen- 
made of 2 parts shingle, passing a 
g-in. mesh, i part sand, and i part 
"Ferrocrete" brand Portland cement. 
The tubes were made in hand- 
press machines of 7-5 parts cokr 
breeze, 5 parts sand, and i part Port- 
land cement. These tubes wer.- 
placed between and resting on thf 
offsets on the ribs, and were con 
creted over with a topping of 
concrete composed of i part Port- 
land cement, 3 parts shingle, passing 
a §-in. mesh, the top being trowelled 
to a smooth surface. The slabs 
rested 9 in. and 10 in. at each end on 
York stone templates 3i in. thick, 
bedded on short lengths of brick wall^ 
3 ft. 9 in. long. 13! in. thick, about 
I ft. 9 in. or 2 ft. high above ground. 




.^6 






THSTS. 



ll 
1 


i 


1 


1 


isi! 


? 


1 








\ 


i 


^ 




9 


S 


1 

_5 


' 


« 


?! 




? 


?, 


$ 


f 


V 


% 


S 


n" 


5 


s 


- 


1 1 




c? 


1 


"If! 

J3 u rt 


5 f 


? 


1 


1 


r 


£ 


s 


o 


f 


rs 


? 


1 


s 


_"* 


^ 


1 


■^ 


c> 


s 




t 


1 


^' 


30 


„ 


r^ 


S- 


1 


O* 


f 


?; 


1 


1 


J3 


111 
Q " 


1 


ll 




1 




III 


< 


Q 03 




1 , 




1 s|^.~"| 




•^1 


^ 


%, 


t 


Is 


-If jl I 

S-c iS-c a, S-3 
H H H H 


Si *s -sir ^-3 

H H H H 


^■^ S-oa. -S-s 
H H H H 




1; 


n 


^ 



The load was 
applied by means of 
blocks of concrete, 
each about i8 in. by 
12 in. by 9 in., each 
being weighed, and 
the weight marked on 
it. Care was taken 
to prevent arching of 
the load, the arrange- 
ment of loading being 
as shown in Fif;s. i6 
and 1 8. 

TESTS WITH 

TRUSSED 

BARS. 

The following are 
particulars of tests 
on various construc- 
tions in which the 
" Kahn " bar was 
employed, chiefly as 
a reinforcement, by 
the Trussed Concrete 
Steel Co.. Ltd. 

The test conduc- 
ted for the Bank of 
England was on 
beams and slabs. It 
will be seen from the 
diagram that the floor 
slab was supported 
by main beams and 
a wall, and in the 
centre by a subsidiary 
beam, 15 ft. g in. 
span, 12 in. wide by 
20 in. deep, rein- 
forced with two 1} in. 
trussed bars. The 
allowable deflection 
of the beam was 
specified not to ex- 
ceed iijj of the span 
— !•<'■. ROB by 189= 
J in., with a load of 
450 lb. per ft. super. 
The decking slab was 
sin. thick, reinforced 
with i-in. trussed 
bars spaced 12 in. 
centre to centre. 

.■\s regards the 
material used, the 
aggregates consisted 
of crushed Thames 
ballast and sand, 
while the cement was 
of the " Ferrocrete " 
brand. Two parts of 



TESTS. 



[CQNCBETFJ 



the ballast were mixed with i of sand, and 5 parts of the final mixture were mixeil with i of 
cement, so that the proportions of the concrete were 3 J ballast, i| sand to i of cement. The age 
of the floor at the time of the test was 67 days. 






The loail was applied by means of bricks piled upon an area measuring 15 ft. 9 in. by 13 ft. : 
204I sq. ft. Deflection was taken at two points — namely, one at the centre of the subsidiary beam i 

38 



^ t:NCUNttJ;lN( 



iALi 



TESTS. 




ihe r,M,tro „l tlu- flu„r slab, and the other at the cenlre of the end main beam. These two deflecto- 
..K-tersconsHted of levers which, in recording, multiplied by ten the aotnal deflections of the beams, 
ihe defJection of the subsidiary beam was obtained by deducting from that registered by its defiecto- 
ineter the amount of the deflection shown by the dcflcctometer under the main beam. 

The slab was first loaded with ,00 lb per sq. ft,, for which it was designed. This load produced 

pmctically no de- 

H' < tion in the 

' ondary beam. 

I ventually a load 

"f 125,390 lb. was 

ivenly distributed 

"\'er the area, 

giving a load of 

1 J lb. per ft. super. 

'■ deflection was 

' rtained to be 

1. As the clear 

.•>(>an of the beam 

was 15 ft. 9 in. — 

iSy in. — the defiec- 

lion was, therefore, 

; by rJo = lAii 

p.irt of the span. 

.•\ reinforced 
i.'ncrctf pillar or 
post square in cross 
section was tested 
in June, 1907, by 
Messrs. William 
Kirkaldy & Son. 
I'ig. 19 shows 
the arrangement of 
the reinforcement, 
which consisted of 
four trussed bar 
of the standard 
section, known as 
J in. by li in. 
])laced vertically in 
the angles of the 
post near the 
outside. The tumed- 
up wings of the 
bars were placed 
inwards so as to 
e.Ktend nearly to 
the centre, thus 
ser\'ing the purpose 
of binding wires or 
links to prevent the 
bars bulging out- 
wards under stress. 
Small binding wires 
were used at the 
two ends to keep 
the rods in posi- 
tion while the 
and its length was 




- I^ETAIL OF -TF ^^■T si^AB — 



The post measured 121 in. on each face 



cjncrete was being rammed. 

ITd 'mesh^'^^^'"f ', """" '."""''T'^ ' •''^'^ '•"""^'' '=™^^*='^ ^"<1 ^'^^^^"^d to pass"Throug"h 
a i-m. mesh sieve, first mi.xed with i part sand passed through a fin. mesh sieve Of this 

n?t :" I^h'"'; 'T "T ""^ '"'^^'' ""*- ' P^^' °^<=^""^'^'- '^ '-^^y drv mixture wa used, and the 
post moulded vertically, the concrete being tamped in position with a J-in. rod used as a rammer. 



39 



TESTS. 



[QO NCBETE] 



The post was compressed iii Kirkaldy's huge horizontal testing machine. Half the weight of 
the test piece was taken by suspension at the centre. Fig. 2i shows how the post crushed at one end, 
and Fi". 22 shows the post after removal from the machine. The area of the post was i45'i sq. in. 
The section of each bar used for reinforcing was 0-38 sq. in., a total of 1-52 sq. in. for the four bars, but 
deducting the flanges which were turned inwards in the form of wings the area becomes 025 sq. in. 
The four bars, therefore, gave a total section of i sq. in., or 0-69 per cent, of the area of the post. The 
post sustained an ultimate stress of 326,800 lb., equal to I45'9 tons. The depressions in inches at 
gradually increasing stresses (recorded in lb.) were as follows : — 



3 


■008 


1 


g 


1 


1 


1 
■033 


g 

q 


§ 
I 


§ 


1 


1 


1 


i 


04 


■"■-' 


•oi6 


■o.r 


■0.7 


■040 


■046 


■053 


■060 


■o6g 


•080 


•090 



About the same time two columns, 8 ft. long and 10 in. square, 
each reinforced with four J-in. Kahn bars, were also tested by 
Messrs. Kirkaldy for the Hammersmith Public Baths and Wash- 
houses. The concrete was composed of clean, sharp, broken flint 
gravel of various sizes between J and J in., mixed with sand 
and cement in the following proportions: Gravel, 27 cu. ft.; sand, 
13^ cu. ft. ; cement, 6J cwt. This results in a mixture of approxi 
mately 4 to i. 

The cement supplied was required generally to conform to 
the British Standard Specification, with the following alterations 
to such specifications : — 

To have no residue on a sieve of 5,776 meshes per sq. in. 

Not more than 5 per cent, on a sieve of 14,400 meshes per sq. in. 

Not more than 14 per cent, on a sieve of 32,400 meshes per sq. in. 
and the test for tensile strength when mixed with sand in the pro- 
portion of 3 parts of standard sand to i of cement by weight was 
tobe— 

At 7 days from gauging, 200 lb. per sq. in. 

At 14 days from gauging, 275 lb. per sq. in. 

At 28 days from gauging, 350 lb. per sq. in 
The expansion under le Chatelier's apparatus shall not exceed : — 

2 millimetres after 24 hours' aeration. 

I millimetre after 7 days' aeration. 
Cubes of concrete 6 in. square, made from the materials 
employed, were crushed by Messrs. Kirkaldy & Sons in May, 1907. 
Ten specimens were experimented upon, with the following average 
results : — 



Date when 
made 


Weight, drv, 
in lbs. 


Crushed at tons per 
sq. ft. 


No record 

November iqth, 1906 
January loth, 1907 


18-32 
1815 
17-92 


143-0 
142-7 
104-2 




ELEVATieM 
4- lr'xl5;"Kaln^ Trussed Barii 

/2-/" 




PLA.M 



One specimen crushed at 170 tons per sq. ft. 

The steel bars were required to bear a tensile stress of not 
less than 2S or more than 32 tons per sq. in. without breaking, 
and to elongate at fracture 20 per cent, in a length of 8 in. 

The average yield point of the specimens was 22-2 tons per 
sq. in., and the average maximum stress borne was 32-3 tons. 

The columns were 8 months old, and crushed at 99 and io7 pjg. 20. "Diagram of Reinforcemen 
tons respectively. °f Test Post. 

The above materials were the same as used for the arched roof trusses at the Baths, which were 
also tested by Messrs. Kirkaldy, as per details below. (See Fig. 20). 

The reinforcement of the stanchions below the gallery consisted of six ij-in. Kahn bars, above 
the gallery of nine ij-in. Kahn bars, which were carried round the principals with the addition of 



40 



1, CION.M PWC'IIONA 11 
">.HN(.INli.t-WINl. ~-\ 



TESTS 




TESTS. 



[CDNCBETEJ 







TABLE 3REWI/1G 


10AD5 


APPLLED TO 


POOP B DEP[£CTIQy" 


CAUSED 


ib^ 5AA\[L 






A 




B 7 C ,. 


D 


E 


F 1" G 1 H 


1 


J 


K 


W 


T.W. 


D 


w 




D Iw 


T.W 


D 


w 


T.W 




D 




T.W 


1 D W 




D 


w 


T.W. 


D 


W ITW. 


D 


D 


D 


>.> 






v^ 




/' »™ 




; 


r." 


»n 




„ 


**^ 


*•> 


"o VoZ 


„>o. 


• J 


»^ 


/OJ/ 


" 


J^iJ IO,S 




I 




)ac 


/Sfi 




SCO 


>SJl 


X B-OOO 


llSOi 


IS 


moo 


J6*J 


/J 


/ 


/!?«' 


2t if 


c Soao 


z/Soi 





5«J 


/tf 9/ 


:> 


S Oo IS IS 




o 


Olt 


'Z 


="" 




"" 


")/' 


"f ?r! 


JTJOt 


* 


"tZ 


21" 


1° 


'i 


"^ 


Z'oT^M'Z 


2fyot 


'„ 


;^ 


iJS 


i 


'iZ "'is 




° 


OM 




6 Tvns 2S9 curs. » '"^^ ^ ^v cw/j 




Cx£v Jaat i^^iUd ai3 


/hs 3/de ^f>r/7?OJiaIi cnly 




Jeo uii t *OQ 


ZS it ^ oo K so f .*.oo 4«*S ^ f m / J r o 


C!2 


*oo 19 fz S *oo 


20 il 3 * oc «» / *OC S1.6S O 1 \ t 3 


0)3 


*0O J3 /3 i * OC 


3S 31 I *OC *TSO O *00 na / / / 1 " 3 10 


Oil 


4X, !7'S: 3 < O" 


from tsscim' tToniZspcim 

6xfra hal afib/iej OB this safe /o ecu^iie loasi oa pnrxipals 
















i« £« i^|5;j"j i» ";; tz'iZ 


°^ 










9TC 


nst^ctrrs 


















"" 


mt 




'J 













K Jav:t retrt otnaf & atjiiie jf^Aiwvy s.'vc 
.ffck ■^ VV - ITx^ight^applifd hah axhunJr^ &/eifhfi.MeJrjt tm^t^Pmimng ^e u^ei^<^\%e crodk 
X W. - 72^/ uugf^ goodie and applied hods 

D - TAe de/Jet/ion o/ Ihe Uvfrs m loa^ par^ j/an inch 

Tie aonsirnt' of &t Inrrz mc^ k dnr^rxkd a3 /hey zm-f inart al^el9d i;^ ^ ' 
sprffiQ of fix i&iqinj ffia/? ^e /nokrmenti in flie nx^ prmc^h 
K - T^ff de/fectfoni oiitn'ed fy Aenc /(irkatdy a Sort S7 f^ieoni qf^a (p/^bfnefsr ^ofyf tenff^ 'ni/lmf/f>: 



DEAD LOAD on O/IE 5IDE of ttie. PRI/1CIPAL5 



two i-in. Kahn bars extending for i8 ft. at the crown of the arch ; that to the buttress on the left 
side of the diagram consisted of two li-in. Kahn bars, and on the right side of four i-in. Kahn bars, 
carried over the arches extending across the corridor. There were also two i}-in. Kahn bars carried 
round the secondary trusses supporting the skylight. The average overlapping of the bars was 
6 ft., no welding being allowed. In each stanchion, which measured 12 in. by r8 in., there was thus 
embedded 14 sq. in. of steel reinforcement. 

The large purlins were reinforced with two J-in. bars, and the smaller ones for carrying the 
fibrous plaster ceiling with one J-in. Kahn bar. 

The side canti- 
lever galleries were 
constructed with 
brackets opposite to 
the principals, having 
I-in. diagonal round 
bars carried across 
the air space, and 
reinforced between 
these brackets with 
\ - in. Kahn bars 
spaced 15 in. apart. 
Two 8-in. Kahn bars 
fixed longitudinally 
between these brack- 
ets were placed next 
the wall, and also 
beneath the step 
formed in the gallery. 
In addition, round 

rods I in. in diameter were placed on the outer edge and all round the gallery ; also a i-in. Kahn bar 
in the wall at the upper side of the same, and around which the i-in. diagonal bars were hooked. 

The reinforcement in the concrete bases built by the general contractors below the ground floor 
level consisted of nine li-in. diameter round bars. 

The Local Government Board, in giving their sanction to a loan for the erection of the public 
baths and wash-houses, informed the Hammersmith Borough Council that such sanction could not 
be given for any work in the walls and roof of the first-class bath which involved the use of reinforced 
concrete, but that the Board W(:)uld be prepared to consider the matter further if the B':)rough Council 



WtlCMT or SLOCItIC POBTIOn or ROOF 


VILIC^H-r or ^KyLlCH-r B U£AD FLAT 


Det.lPTrOh. 


LENCTn 


mom 


js^sa 


.,ES*r 


IlfKKPTHlN 


LZncrm 


wtrrm 


WDCHT BK» rr SUPCB 


JlShr 


^'^i'& 


'"' 


"." 


i>2 Oy, 




'/Z?£/£/- 


".'' 


2'1' 


lh2Soy, 


T 




■SilSm 






, I 




'tsr 








^.r 




fhUs 




























*° 




'„zAt)/^ 


\ ■ 


*" 


312 


^■r 


612 
9S t 


f,a,.g 






20 








Jfu..J^ 










2S'6' 


190' 


1* * 


&X-* It, 


yi^^irs 




■«*• 


A 


,^ <b 


iso 


/ d,r„io/id 


mr 3h»iffA.B.C 1 ii.s.ocu,» 
'^ ajl.l ) 


&tf 


»« 


7t 




'%t 


Ueiqhl- 


/■ J/iJio^ Uyor lyif 1 




Sits* 




1 \ Us o^ \ !ij o, /o,^ Caxa.lbHwl at»,t fimil- D 2t « c. 


i/vrj trials 


2S i 


9 


f! 


}^2 S 






n3c of 












Zoix/ (3^ ftie cr^/e 



42 



f J, C&N.vreilCTIONAll 
[t^ t.NdlNt.l-.PINli — 1 



TESTS. 




TESTS. 



ICDNCBETEJ 



would undertake to test one or more ribs after erection in the presence of one of the Board's engineering 
inspectors, such test to be carried out under the supervision of an independent expert. 

■ The Hammersmith Borough Council wished to take up the loan, and the architect was instructed 
to make the necessary arrangements to test two of the principals. In conjunction with Mr. David 
Kirkaldy it was decided that the load should be applied in as near as possible a manner as the 
ultimate load which was to be borne by the principals, and for this purpose cradles were slung from 
two of the principals. 

The ultimate weight of the roofing materials was ascertained from weighing various specimens, 
showing the deadload on one side of the principals. The manner of applying the load was by means 




of bags filled with ballast, each bag weighing i cwt. These bags were all checked in weight, and a 
large number were taken haphazard and checked in weight by Mr. Kirkaldy. 

The deflections were observed by Mr. D. Kirkaldy from the south side of the principals by means 
of a cathetometer sighting on to a mirror having crossed hairs on its face and suspended by two wires, 
which ware attached to the upper part of the rib and held in position by loose rings. Separate 
readings were taken by the Local Government engineers and the architect of lever indicators fixed 
at the various points shown, on to bearers bolted to the staging used for carrying centering employed 
to erect the ribs, but the movements of these levers must be disregarded as several of the ropes sus- 
pending the cradles stretched to such an e.\te.it as to displace the lever indicators, and when reset 
it was noted that the effect of moving the large weight used for testing from the staging on the cradles 
caused the former to spring. 

There was no spread at the abutments, as shown by the readings taken by means of a horizontal 
wire fixed at one end, carried over a pu'ley, with a weight attached at the other end of the wire. The 
readings of the pointer show that no movement took place. The roof was superloaded to an extent 
of 50 per cent, of the permanent dead load. The greatest deflection measured was only ^^gth part 
of an inch. And after the removal of the load the roof principals were found on testing to have 
recovered- their original form; in fact, the reading on the cathetometer was above zero, the reason 
for this being that the cathetometer was set to zero after the cradles were hung, but it showed con- 
clusiveh' that there was no permanent deflection. 

iTo be coniiniicd.) 

44 



M 



RECHXr IKXTliNTS. 



RECENT BRITISH PATENTS 
RELATING TO CONCRETE, 

W^ propose to present M interjuls pjtr-tlculars of Brttisb PMents issued in con- 
nt\tion 'With concrete .vij reinforced concrete. Tliese particulars ftave teen prepared 
for this lournal t-y Mr. A. W. Farnsviorth. of Strand Chambers, Derby.— ED. 

Concrete Floors for Small Residences. — \o. ijS8£Jo8. SocUU E. I'crrand 
ct I'ntdcaii. Acccplcii .\ovcniber 2yjoS. — I'lie use of reinforced concrete n(x>rs 
ill sni.iller residential buildings is considerably restricted by the heavy cost of center- 
ing, and a general dislike to the 
Ix'anis projecting below the ceiling. 
Recent efforts to overcome the difli- 
cultv have resulted in the hollow 
beams, which are brought to the 
building ready-made and laid close 
together, but the inventors stale 
that as lathing is required for the 
ceilings they do not consider the 
system satisfactory. They propose 
to use hollow plaster cores (A), 
which act as moulds w'hen the con- 
crete is filk'd in and afterwards remain in ]>osition 
of the beams (E), and alTordin 
reinforcement 
illustration. 

An American Proposal.-No. ;.5v./0. Churlc 
2()/oA'.— This is another attempt to obtain 
reinforcement during the pri:)cess of filling 
readilv seen that the inventor's idea consists i 




uppi>ned l)y the undercut sides 

surface (C) for a suitable plaster finish. As the 

s in no wav interfered with bv this arrangement, it is omitted in the 




E. r.iriKv. .Accepted November 
rigidity in the fixing of the 
From the figure it will be 
intertwining several bars to form 
the main tension 
member (lo) of the 
beam. At points 
Where the bending 
moment decreases 
some of the twisted 
bars may be bent 
upwards to receive 
the tensile shearing 
stresses, and in con- 
tinuous girders, 

where a negative bending moment occurs at the points of support, the shear inem- 

bers can again be twisted together to form the reinforcement (12). It is claimed 

that the invention permits accurate distribution of the steel according to the stresses 

in tin- licam, and that tile shear members are securely held in position, as they 

lorni pail of the tcnsiun members. 

Rigidity In Construction. So. idy/jloS. R. Hermanns. Accepted De- 
cember jjoS. — When hollow filling blocks are used in reinforced concrete 

floors in order to provide a suitable surface for ceilings and other reasons, 

it is pointed out that the position 

of the reinforcement in the 

beams may be easily maintained 

in a thoroughly reliable manner 

by the simple device described in 

the specification. During the 

manufacture of the blocks (i), 

steel rods (2) are built into them 

and project on each side far 

enough to receive the reinforcing 

bars (3) in the hooked ends. 

When placed in position, before 

the concrete is filled in, small 







RECENT PATENTS. 



[CONCBETEi 



clamps (4) are placed over the bars at the points of support. It is stated that, pro- 
vided the reinforcement is sufficiently well supported to avoid saKg^ing, it is very easy, 
when this method is in use, for the responsible persons to be certain that the bars 
are not displaced during the filling-iii and ramming'. 

Floors without Centering. — A' 

10108. — In tlie figure is shown 



mother 



),S'. ir. Ilcrhst. Accepted December 
of the many systems of reinforced 
concrete floors that may be erected 
without centerings. Here the floor 
is framed with previously pre- 
pared beams (r), m.ide with suit- 
able projecting angles (s) to receive 
and supiK>rt the remainder of the 
work. Bridge pieces (a), placed be- 
tween the Joists and resting on the 
angles (s), carry in turn filling slabs 
(b and c). The actual floor is laid on 
I he upjxT slabs (b), and the ceiling 
Ijlaster (g) is applied to the face of 
the lower slabs (c). Several modifica- 
tions of the proposal are described in 
tiie specification, but in all cases the 
leading feature is the construction of floors with joists brought to the job ready made. 

Another Reinforcement- Vi'. jiiS/oS. H. Kempton Dyson. .Accepted December 
ijjoS. — The familiar expanded metal principle is applied to this system, which 
consists in using broad bars of channel section with a thin web and 
moderately thick flanges. The web is slit into a series of strips (.A), which form 





an 0|X'n framework when the flanges of the bar (B and B') are forced apart. The 
accompanying figure shows that the inventor pro]X)ses to use the portions, B, B", as 
the reinforcement required by bending moment, and the sloping strips (C), formed 
from the web of the original bar, are intended to take the tensile stresses induced 
by shear. 

Improved Piles. — No. 2bogi jo8. F. W. Campbell. .Accepted JtDtuary 4I0CJ. — 
The inventor has given considerable attention to the possibility of fracture when piles 
are driven through strata of exceptional hardness. He considers that the risk of 
damage to the concrete might be reduced if a suitable cushion were interposed between 
it and the driving point. The cushion is shown in position at C (Fig. i). .\r\ alterna- 
tive method of relieving the pile from severe shocks is shown in Fig. 4, where two 
driving bars (i, i) are placed outside the concrete and serve to transmit the effect of the 
blows direct to the point. It is stated that the bars can afterwards be withdrawn. 
The head of the ))ile is constructed in the usual ni;uiner. 



Ǥ 






^ 




46 



E 



RHCEST PATENTS. 




Fortifications In Reinforced Concrete. — A'o. 
yfijj <>S. .V. Shilki-a'ilsili. Aacpltd Fcbriuiry iioq. 
Accordiiifj; to llie spfcilic;ui(.ni, altciiipts to pru- 
ducc- a successful concrete armouring for ships 
,ind fortiliciitions liave failed chiefly on account 
of the brittleness of the materials used, even 
u lii-ii reinforced by metallic webs. It is pro- 
posed to substitute for the previous aggrej^ates 
sli'<l turninf^s and other scrap metal. When used on 
ships' sides, as illustrated, litjhter materials than sand 
are suj:;-gested for filling the voids, and are detailed in 
the specification. To avoid ramminff, which mi^ht 
le.id lo excessive weight, the cement is forced into the 
mass through the pipe (5). The timber (3) is simply in- 
tended to act as an elastic backing. In ordinary land 
defences, where weight is of no consideration, the con- 
crete may be rammed in the usual manner. It is 
claimed that concrete made on this system will offer 
excellent resistance to modern artillery. 



ir 



Another Reinforcement, -^o. i^bs^joS. 

II. Jolimon. .Icccpted February 11 jog. — This is 
another attempt to provide a satisfactory metallic 
bond for brickwork, and the material may also 
be adapted to other purposes. As the majority 
of wire mesh nettings are corrug;Ue<l, the 
inventor points out they are not adapted to 
resist tensile strains, and he therefore describes 
in the specification a netting more suitable for 
the purpose. The wire fabric is made of longitudinal 
wires (a, a), all straight and parallel to receive ten- 
sion, interlaced by cross w-ires (b) twisted round them. 
It will be noted th.it the netting can be easily divided , 

by the w illuiraw al of one of the Straight wires. 

Concrete Sleepers. — No. 124.13108. B. dc Kovats. Accepted February iSjog. — 
After dealing with the defects of reinforced concrete sleei>»rs manuf.ictured in the 
conventional rectangular form, the following design is submitted as an im- 
provement. The sleeper is formed in two blocks of sufficient area and united bv a 
bar sulTiciently stiff lo ensure a uniform gauge. Th,e bar is V-shaped in section, so 



//A J 


^^ 


/d\ 


u 


/«Vj 


J^\c 


L.l 


\L 


/^vT 


/?X. 




L. 


y/T^^ 


//y 


1L^:1 







Pig' 4 



that it will sinlv into the ballast and not rupture through bending stresses. Several 
modifications of the design are described, including two separate blocks tied together 
by a steel bar. Wood wedges (8) are built into the concrete to receive the chair 
spikes, and the best arrangement of the reinforcement is shown in Fig. 4. The in- 
ventor claims that the arrangement offers adequate bearing surface without the use of 
awkward lateral wings, and that the liability to fracture from uneven bedding is also 
considerably lessened. 



47 



RECENT PATENTS. 



ICONCBETE 



Annth^r Floor System -No. 6662/0*'. .1. Cray. Accepted March 25,09 -The 
invenir it^cribera^olLTetot to facilitate the erection of floors and to -duce the cost 
of centering,- bv the use of ready-made secondary jo.sts and floor slabs placed betxveen 
or above the 'main beams. The proposed 
joists (A) have tapered sides so that the slabs 
(M), made of anv suitable material, can be 
wedged down between them. If flat ceilings 
arc required the undersides of the slabs can 
be made flush with the lower faces of the 
beams; but in the case of panelled ceilings 
the joists project to receive the decorative 
cornices as illustrated. The percentage and 
disposition of the reinforcement vary accord- 
ing to circumstances. The ends of the joists 
may rest on the lower or upper flanges of 
the main girder. In the second case the 
method shown in /•'/.•;• - '^ suggested, wliich 
consists of making each joist witli a splayed 
end E, hooking the reinforcement b.-irs to- 
gether, and .iflerwards filling in the V-shai)e<l gaj) witli conciet. 




The Reinforcement of Walls. ^ 
FIG I 



/ 




FIG 2 



'^M 



S()0 oH. C. M. h'ocli luul L. 0. Mouclicl 
d~ Partners. Ltd. Accepted April 6 09. 
— The object of the invention is to pro- 
vide reinforcement for walls built of 
bricks or similar units without the in- 
convenience of threading the bars 
through holes in the materials, as sug- 
gested in earlier proposals. The result 
iias been attained by making hori- 
zontal and vertical grooves in each 
brick so that the rods or similar rein- 
forcement may be built in and grouted 
as the work proceeds. The inventors 
explain that the arrangement need not 
interfere with the ordinary methods of 
building, for the bricks can be bonded 
as usual. They also fX)int out that it 
results in a considerable increase of 
strength for the same weight. 



A New Bar and its Uses. — .\o. 22310 joy. E. P. 
Wells. Amended February 22,09. — The invention con- 
sists in forming a light continuous fin along bars of 
anv section. The fin may be perforated, and is strong enough 
to withstand the stresses from the shear memliers or bracing 
w-hich are attached to it. It is claimed for the reinforcement 
that the risk of the diagonals slipping on the tension bars is 
avoided, and there is no necessity to cut into the bars themselves 
in order to m.ake connections. Several drawings accompany 
the specification, showing how readily the bar lends itself to 
the requirements of reinforced concrete construction. .-Xmongst 
them mav be selected Fig. 5, a method of introducing distance 
pieces between the bars, and Fig. 14, a typical column section. 
The advantages of the bars for arches or similar work are also 
dealt with, and reference made to the fact that the reinforcement 
can be securely fastened together so that it forms a light braced 
arch before the concrete is filled in ; consequently, the risk of 
displacement of the steel is reduced. 



/i^.5 




+8 



RECENT PATENTS. 



Apparatus for Wall Bulldlag.—!^'o. 357.;/oS. li. liuu'en. Accepted Marcli 
iijoi).- Ni> part of rL-infurtxxl concrete construction as applied to ordinary buildinfjs 
is more seriously handicapped by the cost of centerin^j than the walls; the device 
introduced by the inventor has been specially desif,'ned to overcome the ditliculty. The 
apparatus consists of a type of travelling; mould which is used for sections of the walls 
in succession, due care beinf; taken to preserve the true alij^nment. The worU is 
started by the construction of the base or footinj^s in the ordinary manner in order 
lo provide a track for the machine. The actual mould consists of two l<X)se sides (h) 
ttilli end pieces (2) clamped tof^elher by catches (i). It is used in the followinj; 
manner : C'ommencinfJ at the end of the wall, the two side plates, which project below 
the top of the footin}j;s, are locked in position with two end plates; the box so formed 
is then lillwl with concrete, and as soon ;is this sets the plates are slacked away and 
the moulds movwl forw.ird for the next lillinf,''. The illustration shows the apparatus 
in this position, and it can be readily seen that t)nly one end plate is required as the 
lirst block serves to close the other end of the mould. Ihe two side plates are suitably 
connected tofjether at each end and travel on runners (v and s) which move alonjj 
temporary tracks (w and u). The tracks are formed on shallow plates, which assist 
the alig'nment of the work, and are move<l forward with the mould as required. It 
is sug'f^ested that the ajjparatus should be made from a lij,'ht metal such as aluminium, 
on account of the frequent handling;, and it is pointed out that any suitable surface 
may be fj;iven to the wall by the use of plates bearinfj; a correspondinj,' pattern. The 
inventor claims that concrete w.alls m.-iy be buili in this marmcr at far less cost than 
w lu-n limber shutterinj.; is used. 




+ ? 



RECEXT PATENTS. 



ICQNCBETEl 



from n.-i 
the mail 



t bars 
1 bar. 



An American Bar. — 

No. 2b-j8bjo8. ,\. Tlunnas. 
Accepted April 2g og. — The 
bar shown in the illustration 
is very similar to other known 
t\'pes where the shear mem- 
bers are attached separately. 
The cross section of the bar 
i> a 'lee with a heavy stem 
(I) intended to resist the 
tensile stresses, and a lig'ht 
table (2), which is notched at 
intervals (4) to receive the 
she a r members. The 
diaj^onals may be formed 

cut U> the required length with their ends bent up under the table of 

as shown at point 3. 




The Manufacture of Hollow Piles— No. 7^55/09. 
ir. J. Stezi'art. Accepted May 20/og. — The formation of 
the projections inside the piles referred to in Specifica- 
tion 7454/09 (see specification below) adds somewhat to 
the difficulty of manufacture, but the inventor points out 
that it may be overcome by making the piles in halves, 
provided they are suitably joined together. The ordinarv 
reinforcement is omitted from the drawings for the sake 
of clearness, but short metal rods (2) to form the connec- 
tion between the two halves of the pile are shown. The 
groove around them may be filled in with cement (^). 





Methods of Driving Reinforced Concrete Piles.— .\o. 7^5^ 09. 
11. J. Sliu'art. Accepted .Mav 2*' 09.-— Several methods of 
driving hollow piles are suggested by the inventor, of 
which the one shown in the illustration is typical. It is 
proposed to form inside the pile a series of shoulders (10), which 
would receive corresponding projections on the driver (ii). Spaces 
are allowed between the projections large enough to permit the 
withdrawal of the driver. These are shown in Fig. 2, and the 
driver itself (3) is also drawn in its working position. Suitable 
cushioning material (6) is introduced between the projections on the 
two objects. 



(& 



CCNSTIHil-nONALl 
E.Nr.rNtEJ<lN(i — J 



reci-:nt i>a Ti-:\"rs. 



.fi^ 1 



The Bracing of Piles below the Water. 

Cottsiderc. Aufplcd June lojoi).- The iiiveiUor 
;iix' sifnt'ially braccxl together above the 
water level, wlion the water is deep they 
are unsupportcxl for a threat part of their 
length. lie has, therefore, d<>vis<?<l an 
arranjjeiiient for lixiiifj diagonal bracing 
of reinforced concrete between them, and 
below the surface of the water. By 
reference to the illustration it will be 
readily seen how this is elTected. The 
diagonal brace (.-\) is constructed with a 
swelled end (B), duly reinforced by the 
rods (C), and provided with a hole large 
enough to iierniit it to slide over the pile 
(D), The socket is retained at its correct 
height by means of a sus|x:nsion wire or 
rope until it is secured by driving home 
the wedge (F). The bottom of the socket 
opening is then ck>sed by the packing ring 
(I), which may be held in position by cords 
luitil the opening is filled with hydraulic 
cement introduced from above through the 
pipe (K). It is stated that the method 
described is a satisfactory means of uniting 
the respective parts of a reinforced con- 
crete structure below the water level. 



A nuaiid-Gabriel 
t although piles 




Improvement in Steel Reinforcement. — Xn. j^q^'oS. Gray &■ 
Ait-cptcd Aiii^iisl ij (M/. The emi)k)vment of heavv reinforcing rods, sa'v of 
diameter and upw.irds, is ac- 
coin])anied by dilliculties in 
bending which entails heat- 
ing. To overcome the ditTi- 
culty and to obtain increased 
rigidity in the steel skeleton, 
the system described in the 
specification is suggested. 
I'or each large bar is substi- 
tuted a group of small rods, 
w hieh may easily be bent cold ; 
they are held together b\ 
U-shaped clips with screwed 
ends and nuts. It will be 
noticed that one end of each 
clip (/) is sufficiently long to 
rest on tlie bottom of the 
mould, in order to maintain 
the bars at the correct height. 
.Across the screwed ends of the 
clips are washer plates (e). 
whose length equals the 
width of the beam ; these 
also fit between the centering, 
thus preventing lateral dis- 
placement. .Several modifica- 
tions of the invention are de- 
scribed in the specification. 




Another Bar.— Xo. ig^g^ oS. D. G. Somerrille. Accepted September ;o 09. — 
The efficiencv of steel reinforcement when embedded in the concrete is obviouslv far 



RECENT PATENTS. 



iLYj^Clikim 



from bein^ ihe only point for consideration : low first cost, convt-nifiice in transport, 
and ease in handling claim equal attention. In an atlrm])t to embody all these 
features in one type 



of bar, the inventor 
has designed the one 
dealt with in the 
specification. It con- 
sists of two or more 
square rods rolled 
together and joined 
by a thin fin l>etween 
the corners, as shown 
in the figure. The 
perforation of the 
fin at frequent inter- 
vals permits the pas- 
sage of the aggre- 
gate and gives 



FIG 5 




FIG 7 



mechanical bond; the diagonal shear members may lie passed through the slots in the 
fin. Where a reversal of stresses is encountered some of the rmls themselves may 
1)1- b.'nl upw.-irds, and it is claime<l th.at they give a larger sectional area of reinforce- 
ment than previous systems where the lins are bent upw.ards. 



A Floor Qlrder.— So. 281^ oi) 
lere is anotlier .attempt to provide an 




/'. va\i l.ccuw. Accepted September ib/og. — 
imomical ready-made reinforced concrete beam 
without undue waste of 
material. The chief feature of 
the design consists in the 
adoption of the parabolic com- 
pression member (g). The 
reinforcement is of the usual 
pattern, but it is claimed that 
the connection of the tension 
and compression rods at (/) is 
an advantage. The beam is 
shown in positioi, and it is st.ited tliat tlie arrangement affords a lluor which is fire- 
|)r<Hif, light, strong. ;ind soundproof. 

A Bar with Mechanical Bond. — Mo. hoo^log. .1. K. l.iudcu. Accepted July 
2g.oi). — The mechanical bond between the concrete and the reinforcement introduced 
by the inventor is obtained bv forming a series of circumferential ridges on a round 
rod. In order to support the 
ridges during rolling thei- are 
connected bv a projection (i) 
formed longitudinally along 
the bar ; all exterior edges are 
rounded, and there are no 
pockets where air or water 

may be trapped. In column or ■» "^ j 

wall construction the ridges 

assist to hold in |>osition anv transverse member which may be 
wise attached to the verticals. 






wfm^ 






^m 



^ired on, or other- 



A Suggestion for the Construction of Sea Walls. — No. 2o^'j-y!o8. J. Troman- 
hauser. Accepted October 2S'O0. — In i)rder to overcome some of the difficulties en- 
countered in m.irine work, the inventor describes in the specification a method of 
sea wall construction which may be partly carried out in sheltered water. A special 
timberraft is first constructed on land and launched. The shell of the wall, or part 
of it, is built up in reinforced concrete on the floating raft forming a f>ontoon which 
requires ballasting slightly with sand or gravel; metal hooks (g) fi.xed to the timber 
are built into the bases of the walls. During the construction a flooding valve (17) 

52 



s 



(XtHSrUUCTKJNA I J 
KNdlNt.EHlW. — J 



RECENT PATENTS. 

U l.uill in .,t .1 caiivoiiknl level. In /•Vi;. 2 the work is shown nearly completed with 
the shutterintf still in position on the upper portion. When the |x>ntoon is finished 
It IS towed into i)<>sition and sunk by opening the v.ilve. In the event of uneven 







^rf^-19 




-ir <-'^ ■'- 



H 4-08 

Fig. 2 

settlement the \\at<-r m; 
justment. When fin.illy 






3 5 6 



4. 



> be i)LimiK-d out and the structure floated a),'ain for read- 
. -unU the interior of the concrete shell may be filled with any 
suitable material. The claim is for the use ol the raft combined with the concrete box 
and the valve for sinking. 



The Sheathing 




. 11. Skinner i'-~ Oneida, Lid. 
Accepted October 28jo().~\t 
has now become the recog- 
nised practice to cover the 
stanchions and beams of steel 
framed buildings with a con- 
crete sheath for fire preven- 
tion [xirposes. It is not, how- 
ever, an easy matter to provide 
a satisfactory armature for the 
concrete by means of netting, 
or similar material. The in- 
ventors' pro|X)sal deals chiefly 
with this difhculty, and bv re- 
ferring to the illustration it 
will be at once seen that it 
consists in witiding chains 
spirally round the steel mem- 
l>ers. Rods (7) are used to 
assist in maintaining the pro- 
per distance between the coils, 
and [>rovision is made for 
tightening the chains. It is 
stated that the system will 
materially reduce the cost of 
this class of work, and that 
the -chains can be applied with 
great speed and accuracy. 



ASSOCIATION OF WATER EXGINEERS. 




[CQNCRETEJ 

1 



RECENT VIEWS ON 
CONCRETE AND REIN^ 
FORCED CONCRETE. 



SOME PAPERS & DISCUSSIONS. 



;* ,c n„r ,nt.nt,on -u r-r,^ ■ ... Papers and D,sc-jss:ons presented before Techmcal 
SoJeties on Liters reUlmg to Concrete and Reinforced Concrete m a concse form, and 
in such a manner as to be easily available for reference purposes. t„ii„„ , 

The method -we are adopting, of d,-oiding the subjects into sections, is, w behe-ue, a 

"""wfTr^Tthat this chapter of cur journal may become a recognised reference medium 
as to the latest -vietus of those who can speak ivith authority.— tJJ. 

THE ASSOCIATION OF WATER ESC I SEERS. 

REINFORCED CONCRETE CONSTRUCTION. 

By Mr HARRY W. TAYLOR. Assoc.M.lnst.C.E. 

Mr Hanx W Tavtor, Assoc.M.lnst.C.E., o/ NewcaslU-on-Ty,u: read a paper on -Reinforced 
Concrete Construct.on - be/ore the members of the Association of Water Engineers, at llu^r recent meelmg 
at Liverpool. 

Factors of Sa/ery.-The author suggested that before designs were prepared the 
follo.'ng particulars should be definitely settled :-(.) The live (- ^PP'lf ,- ^^^J^^^^ 
load ner unit • (') the factor of safety for the live load (usually about 4 ; (3) the tactor 01 
Setrfor the dead load (usually about 3) I (4) the test load (wh.ch should be lA tni.es 

""^ 'por'S^walls and floors of reservoirs, and especially for water towers, the author 
was oropnion that a higher factor of safety should be used, and m h.s experience a 
factor of Tor even 6 was none too much. Water pressure was the most searchn.g of 
Si pres^u?es, and though theoretically a higher factor is not needed, this was essentially 

^ "-^^tV: Sto^'oTLren- a"be'S!4d on the elastic limit of the steel. The live or 
workint load should not exceed one-half of the elastic limit, while the test load should 
not exceed three-quarters of it. Factors of safety were, however, very generally stated 
^nra^o of the breaking weight, and therefore the elastic limit of the steel should be 
doubled whe thi'ratio%vas adopted. .\s an example, with steel '.'hose elastic limit is 
about one-half of its ultimate strength, the factor of safety would be described as 4. 
for one-quarter of the breaking load. 

Design of Centering.-The primary object in designing centering should be ease 
in "Lf.l and facilit^- for quick re-erection, a point of the utmost ■"^P^rtance where 
there is much repetition on a contract. It should never be forgotten that the cost of 
centering was nearlv always a large percentage of the total cost of the structure and 
economy" on this item frequently meant an appreciable sum of monej^ VVhere t was 
possible, and the smaller spans i^rmitted, it was frequently desirable to arrange or the 
floor slab centering to be carried on the secondary beam troughing, and for this 
troughing to be carried in turn on the column boxing. With large beams of consider- 
able span this, generallv speaking, would not be possible, and arrangements must be 
madelor the ^am troughing to be carried by struts. The beam troughingshould be 
so designed that the under o'r bottom board remained in position after the side boards 
and -thi floor centering have been removed. .Ml struts under beams, etc., should be 
wedged from below at the floor level, and not at the top of the struts. 

It was also advisable to cham.fer the arrises of the columns and beams as giving a 
much more pleasing appearance to the work, also to give a camber to the beams of 

5+ 



REINFORCED COSCRETE CONSTRUCTION. 

about i in in i„ It.; if this w;,s nut done, the Ixani, lhouj;h l^rfeclly straiiiht, would 
appear to the eye to saK^at the ce.i.re. The ends of the Ix.uni should be hau du- on 
K ?,'''■'"!■ ''■'•■''' ""• "■••"^ '"''-''''*•'• '^^P^-<--i='".v in continuous beams. Thick timber 
^ener k""" "'^'". "^'"' ^'^ " '^'^'^^ '""'^'^ '""f^'^-^ ""'' «'ood rou^h handling better^nd 
generally speaking, was more economical in the end. In the construction of walls it 
and ndd'Th ■'• ='^'^'=^=','^'';/°.'^-'' "'« outer shuttering first, then place the stc^d in position, 
and add the inner shuttering and concrete as the work proceeds. To keep the inner 
and outer faces of the shuttering for walls the pro,x.r dist.-.nce apart perforated 3 

tifZxTT ''r'''''''' r''' "'"'■ ''' ^"'^ "^""""^''^ "^'•^ '^"'<^ '^^'•'P'"ff 'he shuttering 
of bourse filled' '' ' '''""'''■'"^' ^^" removed the holes left in the concrete were! 

Where a smooth surface to the work was required the face of the timb<.-r touching 
the concrete should be wrought and coated either with mineral oil, boiled soap or 
whitewash. 1 hese also preserve the life of the timber bv preventing the liquid cement 
soaking into the pores of the wc«d. If the surface of the work was to be afterwards 
rendered, boiled so.-,p or vn hitewash may be preferable to oil ; in any case no animal oil 
of an> kind should be used, but only mineral oil such as crude petroleum. \fter all 
he centering was h.xed and coated with oil or soap, and the steel placed in position, 
It was advisable to thoroughly Hush the centering and moulds with water l>e ore anv 
concreting is commenced. ' 

Steelwork-\l would save considerable time if the steel were delivered cut to the 
reqtiired lengths, as by this means a good deal of smith's work on the job would be 
avoided. .\ ccMnvnient way of Ix-nding the smaller bars was to use a long tem,x)rary 
bench, constructed of thick timber « ith strong pins or plugs in same to bend the bars 
upon. Ihese j.ins should be arranged to fonii a template, and thus the work would be 
accurate and ex,>e'ditious. Smooth bars, whether round, square, or hexagonal, must be 
anchored at the ends, either by bending at right angles or bv splitting open like aVish- 
M°L -■jr'',"K' "f.'-'^'-'^h^''- ••'"'' ""t. th^' latter being probably the most effective 
method .Steel bars in floors and walls must be crossed and bars in the beams must be 
cranked over the supports irrespective of the system used. Where openings occur 
either in floors or in walls, ,t was always .-ulvisable to put additional steel round the 
openings. It was alw,-iys preferable to have the inside of the stec-lwork of a column as 
clear and fret> from projections as ,>ossible so that the ramming of.the concrete might 
be thorough, .\rrangements must l>e made for keeping the steel in the column bo.xes in 
Its correct ,x.sition wlYile the concrete was being de|x)sited in them ; this could usuallv be 
done by temporary wedges. The steel bars in the be.ims could either be suspended from 
above or by the stirrups or shear hangers, or they can be carried on temporary wooden 
slips or by concrete bolsters in the bottom of the troughing. 

The bars in floor slabs could be kept the require<l distince above the centerin<>- bv 
me.ins of notched wooden templates, or by a round iron rod; these were pulled aTone 
the floor just in front of the concrete as it was being deposited. .Another method was 
by means of small concrete bkx;ks which were emlx-dded in the concrete and became 
part of the structure. It was in every wav desirable that all or nearlv all bars where 
they cross each other should be « ired together with soft iron wire! thus "-uardina- 
against displacement when the concrete was being rammed around them. 

Concrete. -Good concrete should be dense, that is to sav, containing as few voids 
as possible; in this respect the selection of the gravel and sand was a matter deserving- 
great care and attention. Hitherto it had been the custom to specify that concrete 
should be composeil of so many parts by measure of gravel, so manv parts of sand to 
one part of cement, regardless of the voids in the two materials. This, in the author's 
opinion, was a mistake, and the i)roportion of voids in the gravel and sand should be 
ascertained, so as to obtain as dense and homogeneous a mass as possible. 

Specifications very frequently call for coarse, sharp, clean, gritty sand, but the 
author believed a sand containing a proportion of fine particles was preferable in the 
majority of cases. Of course, a dense concrete was not alwavs needed, such for 
instarice, as internal floors, but where work was required to be weather-tight,' and 
especially water-tight, sand containing a considerable proportion of fine particles was 
in every way preferable. In depositing concrete in the moulds and centering the chief 
object was for it to be homogeneous; if it was dropped from a height (even of 6 or 
7 ft.) the larger stones tended to separate from the mass and honeycombed work would 



55 



ASSOCIATION OF WATER ENGINEERS. [CQNCBETE] 

result. Concrete should not be droi^ped more than a couple of feet; if it must descend 
from a greater height than this, it was better to slide it down a pijie or shoot. In 
ramming concrete, light rammers were preferable to heavy rammers which were apt 
to displace the steelwork. Concrete on small works was invariably mixed by hand, 
while on large contracts a mixer was generally used. If a concrete mixer was used 
the best work would undoubtedly be obtained with a batch mixer as distinct from a 
continuous mixer. If a continuous mixer is used it frequently ha|)pens that the stone 
comes through first, and the cement and sand last, and consequently the result wis 
most unsatisfactory. 

The author's experience was that wet cojicrete was preferable to plastic concrete, 
because it filled the moulds and spaces better and llowod between and around the steel 
bars more freel)'. 

It was frequently the duty of a water engineer to design and construct reservoirs, 
tanks, and water towers, and it was obviously of the greatest importance that the work 
when finished should be watertight. This point was so excellently described in the 
Engineering Record that the author made no apology for quoting the following 
extract from this paper : " The great obstacle hitherto experienced in making water- 
proof concrete has been its highly porous character. With the dry mixtures used in 
times past the porosity of the concrete was excessive, and not the least of the many 
advantages accruing to the use of wet mixtures is the greater solidity and density 
conferred upon the mass. \ wet mixture not only causes all portions of the mass to 
run together in greater solidity, but it enables the finer materials of the aggregate to 
flow freely and thoroughly into the spaces between the coarser particles, thus producing 
a much more continuous and dense interior mass. This obviously ineans a greatly 
reduced permeability to water and a much enhanced capacity to resist seepage through 
it. However much care may be taken in securing a thorough and intimate mixture of 
the component parts, some seepage will generally result under pressures of 40 to 60 
pounds or less ]X'r square inch." 

Whatever materials were used for rendering concrete waterproof they must be such 
as would not affect the strength and durafjility of the concrete. It had been clearly 
established by tests that the presence of a small percentage of fine clay did not 
necessarily injure the strength of the concrete, while it certainly assisted very materially 
in securing a much more waterproof concrete. This was, of course, altogether contrary 
to the former opinions of engineers. The use of soap and alum was fairly well known, 
both applied either as alternate washes on the concrete or as a solution in mixing the 
mortar for cement rendering. The addition of a soap and alum solution to cement 
rendering is undoubtedly beneficial where a watertight surface was required, but it 
must be remembered that if the sand itself was coarse and sharp the resulting work 
would probably not be watertight, there being an insufficient percentage of small 
particles to thoroughly fill all the voids. .\ material which was largely used on the 
Continent for this purpose was powdered pumice stone or " trass." 

Maturing of Concrete. — It was often advisable to make test cubes from the same 
concrete that was being used on the works so as to note the process of hardening. It 
was important that the moulds in which these test cubes were made should be 
thoroughly wet when the concrete was placed in them, or the dry wood would suck the 
moisture out of the concrete, and consequently the test would be of no real value. 
The author, however, preferred to place reliance upon the actual concrete work itself, 
and considers it better practice to test important beams with a chisel to ascertain their 
hardness; if this was done near the neutral axis it would not affect the strength of 
the beam. 

Removal of Centering. — Generally speaking, it would be safe to remove the 
centering from under floor slabs in from 7 to 14 days after the concrete had been 
deposited. The side boards of the beams and the boxing of columns might also be 
removed in about tlie same time. The bottom boards under beams of spans, say, up 
to 20 or 25 ft., should not be removed for at least four weeks, while for longer beans 
an extra length of time for hardening should be allowed. A rule should be made on 
all contracts never to touch the struts under the bottom boards of the beams until the 
concrete had set hard or damage by shear was. almost certain to result. 

Frost and Heat. — It occasionally happened that work had to be finished within 
a given period irrespective of weather conditions, and if such work should be driven 

56 



RODS IN CONCRETE. 

into the winter risk of frosts would be incurred. WIhtc it was feasible and time 
permits, the author thinlcs it better to stop work altogether, and protect that portion 
already done in the best manner possible. This could generally be accomplished by 
covering the concrete with hay or straw about 12 in. thick, with boards or matting on 
the top. Where, however, the work must be finished regardless of frost special |>re- 
cautions must be taken. Probably the simplest way was to heat the gravel and sand 
to about 70° or So° (Kahr.), and use warm water of about 100° temperature in mi.xing 
the concrete. Immediately the concrete had been placed in position it must be i)ro- 
tected by canvas tents connected with salamanders or fires by hot air pijx's. The pipes 
should be pl.iced near the concrete so that the hot air from the fire can pass inside the 
tent formed by the canvas, and so raise the temperature sutTiciently to protect the 
concrete from frost. During hot, dry weather, and es|X'cially where the sun played 
directly upon it, the concrete would dry very rapidly, and provision must be made in 
such cases both for screening the concrete froTii the sun and also for keeping it moist. 
The surface of newly-l.iid concrete should be ki pt in a moist state for not less than six 
or seven days during hot weather. 

Conclusion. — It was frequently contended that reinforced concrete was in its 
infancx , .iiicl that suflicient time had not yet ela[)scd to form a reliable opinion as to its 
lasting qualities. The fact that such a large number of structures had been built, 
esi)ecially during the last 15 years, and had answered their purpose (X'rfectly, was, in 
the author's opinion, reliable evidence as to the strength and durability of these 
structures. It should always be remembered that if a reinforced concrete structure was 
inherently weak it would fail the first lime it was loaded. .As the concrete continues to 
harden for 10 or 15 years its strength increases also, and the author had yet to learn 
of a case where a reinforced concrete structure having been erected, say, for five years, 
had afterwards collapsed. 



AMERICAN SOCIETY FOR TESTING MATERIALS. 

NOTES ON THE BEARING VALUE OF RODS 
EMBEDDED IN CONCRETE. 

Paper by ROBERT A. CUMMINGS. M.Am.Soc.C.E. 

Shear. — It a load is so placed that a reinforced concrete member is subjected to vertical shear, 
we reason that the concrete and the metal reinforcement act togetlier. Our structures are frequently 
designed in accordance with this assumption. 

Three or four years ago, during a convention of this Society, the writer brought to the attention 
of a party of engineers the fallacy of assuming that two such materials act together in shear. Sinoe 
that time the subject has not been publicly discussed. Perhaps this may be accounted for by the 
fact that in the large number of published tests on reinforced concrete beams failure by vertical shear 
has been the exception ; and wherever beams have thus failed, the failure has been attributed to 
insuificient sectional area of concrete. 

The common practice in determining the end shear of beams is to allow so much for the concrete 
and to make up any deficiency with steel at so many thousand pounds per sq. in. of cross-sectional 
area. The basis for such practice camiot be explained satisfactorily. 

While it is quite proper to consider the area of concrete as available for shearing, the steel should 
not be included. It would be more appropriate to regard the relation of the concrete to the steel as 
bearing on the rods, if they are sufficiently anchored and suitably placed. 

Bearlae Value of flo/fs.— .Analogous to the above combination of concrete and rods is that of 
bolts embedded in concrete for attaching brackets to support a load. Neglecting friction, the load 
will ultimately reach the concrete through the bearing of the embedded bolts. What, then, will be 
the bearing value of bolts embedded in concrete in resisting a force acting at right angles to the axis 
of the bolt ? This will naturally depend on two things, the size and rigidity of the bolt and the density 
of the concrete. 

This question recently arose in the writer's practice in connection with methods for supporting 
the centering for concrete arches, also for supporting steel brackets on concrete columns by means 
of embedded bolts projecting from the concrete. These bolts were in single shear and in proper propor- 
tion. The bearing value of the concrete to receive the load from the bolts was unknown. 

The object of the following tests, which were conducted by E. D. McCready, of the Lehigh Valley 

57 



AMERICAN SOCIETY FOR TESTING MATERIALS. 



Testing Laboratory, Alleatown, Pa-, under the direction of the writer, was to obtain the bearing value 
for such bolts. 

Tests were made on J-in. square and |-in. round straight steel rods embedded in a short column 
of concrete with the ends of the rods projecting equally about 3 in. on either side. When the specimen 
was placed in the testing machine, the projecting rods were evenly supported on cast-iron bearings 
which were held in close contact with the concrete. The rods were thus bearing and in double shear. 
Specimens were made to be tested at 30, 60, and 90 days. In all 24 specimens were made — two each 
for each kind of rod and for each period being made from both 1:2:4 and 1:3:6 mLxtures. 
It was not convenient to test the first lot at 30 days, and they were tested at 35 days. These are 
the tests described in this paper. 

Materials.— The concrete for these tests was made from bank sand and gravel screened from the 
sand. The sand was fairly clean and well graded, and of the following composition : — 
Per cent. 

2-0 Passing the 30-raesh sieve 



Passing the 200-mesh sieve 
,, ,, 100 ,, ,, 



3-2 
40 
8-4 
13-6 



Per cent 

22-2 

... 43-6 
... 77-4 

... lOO'O 



The percentage of voids deter 
of the gravel was as follows : — ■ 



ned by shaking down in water was 323 per cent. The composition 



Passing the 



Passing the i-in. mesh 



302 
.56-5 



Per cent. 
gi'S 

... lOO'O 



A standard brand of Portland cement was used : tensile strength, neat 24 hrs. ; 472 lbs. ; seven days, 
903 lbs. ; 28 days, 832 lbs. ; with standard quartz, 3 : i seven days, 234 ; 28 days, 299. Setting 
time, 3 hrs. 20 min., initial ; 7 hrs. 15 min., final. Fineness, 200 sieve, 776 per cent. ; 100 sieve, 93'2 per 
cent. 

Compression cyUnders 8 in. diameter and 16 in. high were made up in the proportion 1:2:4 
and 1:3:6, three for each test at each period. Those tested at 30 days broke as follows : — 
1:2:4 1:3:6 

1,932 603 

1,721 721 

2,127 lbs. 909 

i,u27 per sq. in. 744 lb. per sq. in. 

Method of Testiog.— Bearing test specimens were square columns with a lo-in. by lo-in. base and 
24 in. high. As originally made, each column had a 6-in. footing on one side to give stability to the 
block in testing, because it was first planned to apply pressure at one point only. The specimens 
were made in wooden form which had a J-in. square hole cut through two opposite sides (one of the 
sides being that on which the footing projected, and which we will call the " front "), and exactly the 
same distance from the bottom — just midway between the upper surface of the footing and the top 
of the column. The rod to be embedded was put through these holes and projected equally from front 
and back (about 3 in.K This latter fact permitted a change in the original plan, and the specimen, 
were tested in double shear. 

For this purpose two iron castings were made, J in. in thickness, and in vertical section dive an 
inverted letter T, the base of which was 5 in. and the height 12 in. These castings were 14 in. long, 
and served as supports for the test specimens, the projecting rods bearing on either support. The 
supports were held close to the concrete by iron bolts extending through both castings, about li in. 
from either ed.ge and 2 in. from the top. The bolts were threaded on each end so that the supporting 
plates could be drawn to contact with the concrete. 

Pressure was apphed through a ij-in. rotmd bar on top of the specimen, at right angles to the 
direction of the embedded bar. The load was applied in increments of 1,000 lbs. each, careful measure- 
ments being taken and observations made after each loading to determine the deflection of the bar, 
and note the condition of the concrete. Measurements were made with an inside micromoter and 
checked with an inside caliper and outside micrometer. Electrical contact was used. 

Contact points were marked on the upper surface of the projecting bar, right against the surface 
of the concrete and on the upper side of a specially designed iron frame attached to the concrete column 
by four pointed set screws. This frame was attached at a height of about an inch above the projecting 
rod, in order to avoid, as far as possible, all error due to crushing or compression of the concrete. An 
extension above the frame was provided for the upper point of contact, which was 4 to 5 in. above 
the rod. 

58 



fy.COM.TT-WKTKMAIJ 



BEARINC, VALUE OF RODS IN CONCRETE. 



' Descrlplloa of the 7"esf». — Failure in oacli rase was caused liy the beiulmu of the rod for atjout 
an ineh in fnnn tlic surface of the concrete, causing the latter to powder and crumble, and finally 
scale off to a di|itii of \ in. to J in. The surface area thus scaled ofl varied from iV in. to 3 in. in 
diameter, according to the nature of the aggregate at the surface at that point. When the rod began 
to bend and the scaling off of the concrete was noticed, the test was practically at an end as the rod 
simply continued to bend, and it was not possible to increase the loading. In those cases where several 
thousand pounds were added to the load after the breaking out of the concrete before complete failure 
occurred, the rod was supported by one or more large pebbles which had not broken out. 

This scries of tests suggests that the subject of the bearing value of rods embedded in concrete 
should be more fully investigated with reference to the effect of the size, shape, and rigidity of the rod 
as^well as the character of the concrete. No final conclusions can be drawn from a single series of 
tests. In fact the whole subject of reinforced concrete is an undeveloped and fascinating field, and we 
are wofully in the dark as to interna! stresses and the influence of variations in the position and amount 
of embedded reinforcement, witness the extraordinary varietv of systems of reinforcement and the 
disagreement of authorities except as to simple stresses. 

Table Showing Deflectloni. 



I.'t.ll 

Pressure, 


J 111, Square Rods 


i 


in. Koi 


nd K ..1, 




















lbs. 


No. I, 


No. I, 


No. 3, 


No. 3, 


No. I, > 


«'o. I. 


No. 2, I 


•Jo. 2, 




Front 


liack 


1-ront 


Back 


I'roiit 


lack 


l-'ront 


Back 








Concre 


e I : 2 : 4 










1,000 


•003 


■001 


■000 


•000 


■001 


000 


■000 


000 


;.r.oo 


•003 


•001 


•002 


•001 


•005 


000 


•003 


001 


3.. UK) 


•005 


■003 


•005 


•004 


•007 


005 


•005 


004 


■ l.ono 


■006 


•005 


•010 


•007 


•ooS 


007 


•007 


007 


S.ooo 


■008 


•010 


•014 


•009 


■010 


009 


•ooS 


009 


6,ouo 


•oog 


•012 


•017 


•on 


•013 


on 


•010 


010 


7,000 


•013 


■oiS 


•022 


•016 


•019 


016 


•013 


015 


i>,ooo 


•018 


•025 


•028 


•020 


•037 


021 


•016 


017 


Q.OOO 


•021 


■033 


•035 


•035 


•035* 


026* 


•020 


03 1 


10,000 


•028 


■040 


•043* 


•031 


•04. i 


033 


•025 


025 


1 1 ,000 


•034 


•046 


•ofw 


•040 


•066 


042 


■038* 


037 


I J, 000 


•044 


■051 


•072 


•048 


•0S4 


060 


•o(5 


030* 


1 3,000 


•051 . 


•055 


•094 


•061 • 


•lOI 


077 


•obit 


03St 


1-1,000 


•066 


•060 


•no 


•oSo 


•136 


091 


•095 


080 


I. s.ooo 


•073 


•080 


•157 


•113 


■133 + 


not 


— 


— 




•oSi 


•093 


•205t 


•160 


•M5 


127 


— 


— 


17,000 


•104 


•III 


•?6o 


•220t 


— 


— 


— 


— 




■135 


■127 





— 


— 


— - 


— 


—~ 


10.000 


■it)8 


•230 


— 


— 


— 


— 


— 


— 


;o,noo 






Concre 


e I :3:6 










1. 000 


■000 


•000 




002 


•000 


•000 


000 


■000 


003 


:.ooo 


■005 


•003 




002 


•000 


•003 


001 


•005 


006 


3,000 


■010 


■005 




004 


•003 


•007 


003 


•006 


009 


4.ono 


■015 


•007 




007 


•005 


•009 


od6 


•007 


on 


S.ooo 


■020 


•010 




008 


•006 


•01 i 


010 


•012 


014 


I. .000 


■024 


•015 




010 


•008 


•018 


012 


•014 


016 


7.000 


•030 


•017 




016 


•on 


■022 


014 


•018 


030 


fi.OOO 


■036 


•03 1 




021 


•oi6 


•029 


020 


•033 


033 


0.000 


•041 


•036 




020' 


•034* 


■033 


029 


•03 8 


039* 


II'. 000 


■056 


•030 




"38 . 


•P33 


•040 


032 


•041* 


060 


11,000 


■050 


•031 




o.ii « 


•040 


•038* 


on 


•O.S3 


077 


i.;,ooo 


•068 


•033 




095t . 


•oS2t 


■070 


066 • 


■080+ 


093 


13,000 


■075 


•037* 




156 , 


•125 


•095 + 


oS, 


•037 


i3ot 


14,000 


■084 


•041 




169 1 


■147 


■130 


nit 


— 


^ 




•094t 


•04.i 


■195 , 


•160 





— 


— 


— 


16.000 


■130 


•069 


— 


— 





— 


— 


— 


17.000 


■158 


•oSit 


— 


— 





— 


— 


— 


I. s.ooo 


•201 


•115 


— 


— 





— 


— 


— 


lO.O'M-i 


•29S 


•305 


— 


— 





— 


— 


— 


-"■■""-"' 




— 


— 


— 


^ 


— 


— 





* Cement coramenced to powder under the rod. 
t Cement commenced to crumble under the rod. 



59 



AMERICAN SOCIETY FOR TESTIXG MATERIALS, (CDMZK^^i^ 
AMERICAN SOCIETY FOR TESTING MATERIALS. 

TESTS OF CONCRETE COLUMNS. 

Paper by Mr. O. WITHEY. 

This was the title of a valuable paper by Mr. O. Wither. In his absence it was read by Professor 
Turneaure before the above Society. 

The pajxT consisted of a reix>rt on tests of ])lain and reinforced concrete columns made in 
the laboratory for testintj materials in the University of Wisconsin during the past )ear. 
Preliminary tests were first made upon twenty columns. The various experiments included 
plain columns, columns reinforced with lattit~ed angle structural steel, columns reinforced 
with high carbon steel spirals, columns reinforced with spirals and vertical steel rods 
and columns reinforced with vertical steel rods and ties a foot apart. .A more extended 
series of tests was made then on thirty-two columns containing spiral reinforcement, 
the variables being percentage of vertical steel and i^ercentage of spiral steel and 
richness of mix. 

The general character of the results was shown on diagrams which were explained 
in detail by Professor Turneaure. The paper comprised only a brief discussion of the 
main features of the test, as a more complete account of the preliminary series will 
be found in the bulletin of the University of Wisconsin, now in the press. From the 
results of the tests the following conclusions were presented by the author : — 

1. A small amount, ^ to i per cent., of closely-spaced lateral reinforcement, such 
as the spirals used, will greatly increase the toughness and ultimate strength of a 
concrete beam, but does not materially affect the yield point. More than i per cent, 
of lateral reinforcement does not appear to be necessary. 

2. Vertical steel in combination with such a lateral reinforcement raises the 
yield point and ultimate strength of the column and increases its stilTness. Columns 
reinforced with vertical steel only are brittle and fail suddenly when the yield point 
of the steel is reached, but are considerablv stronger than plain columns made from 
the same grade of concrete. 

3. Increasing the amount of cement in a spirally reinforced column increases the 
strength and stiffness of the column. A column made of rich concrete or mortar, and 
containing small percentages of longitudinal and lateral reinforcement, is without 
doubt fully as stiff and strong and more economical than one made from a leaner 
mix reinforced with considerably more steel. In these tests, doubling the amount of 
cement increased the yield point and ultimate strength of the columns without 
vertical steel, about 100 per cent, and added about 50 per cent, to the strength of 
those with 6 i/io f>er cent, vertical steel. 

4. From the behaviour of the columns reinforced with spirals and vertical steel, 
under test and the results computed, it would seem that a static load, equal to 35 to 
40 per cent, of the yield |x>int, would be a safe working load. 

5. The results obtained from tests of columns reinforced with structural steel 
indicate that such columns have considerable strength and toughness, and that the steel 
and concrete act in unison up to the yield point of the former. The shell of the 
concrete will remain intact until the yield point of the steel is reached, but no 
allowance should be made for its strength and stiffness. 

6. As many of the blotters on the tops and bottoms of the columns bore imprints 
of the vertical steel after failure, it would seem a safe precaution to use bed plates 
at the foundations for such columns and thus prevent any fKDSsibility of the steel 
punching through the concrete under an excessive load. 



60 



BRIDGET AT CHIXCFORD. 



NEW WORKS IN CONCRETE 

AT HOME AND ABROAD. 

Under this heading reliable tnformattori ivilt be presented of ne*w 'works in course of 
construction or completed, jnd the examples selected ivtll te from Ml parts of the "world. 
It is not the intention to describe these ^uorks in detail, but rather to indicate their existence 
and illustrate their primary features, at the most explaining the idea 'which served as a basts 
for the design.— ED. 



REINFORCED CONCRETE BRIDGES AT CHINGFORD. 

A MMHKK of rtinforced concrcti' bridfjes are being erected in connection with the work 
III tlie Metropolitan Water Hoard's new reservoir at Chingford for facilitating the 
water su])])ly tliere. 

The worl< at Chintjldnl comprises a lari;c nservoir in the l.ea valley, south of 
ICnfield L(k1<, which will have a capacity of tiiree million tjallons, with a water area 
of 416 acres, and will necessitate the construction of over four miles of embankment. 

An ovcrllow channel from ihe I,ea naviijation has been constructed to conduct the 
surplus water past the reservoir embankment. At this point the towing path is 
carried .across the overflow on a reinforced concrete bridge, of which we give an 
illii^IralicMi. 

Anolhi'r l>ri<lge of similar material carrying the m.ain Ponders End Chingford 
Koad, whicli has been widened for about a mile, is also completed. This bridge is 
furmi-d of three spans each z- ft. (1 in. wide, with a rise of 5 ft. 

Two reinforced concrete arch bridges of 55 ft. sjxin and 5 ft. (1 in. rise have also 
been built across the River Le.i diversion, and on page 63 we show a view of the 
arches for one of these. In addition to the above there are two smaller bridges with 
water towers. 

All the reinforced concrete Wdrk in connection with these bridges, of which there are 




Side View of Bridge o% 
Reinforced Conxrete Bridge . 



NEW WORKS IN CONCRETE. 



[CQNCBETEJ 




BRIDGES AT CHINGFORl). 



seven in .ill, is iK-in^f c.irric-d out by the Colunibi.iii l-ireprtKifinf^ Co., Ltd., of 37 Kiny 
William .Street, E.C. Round steel rixls of various diameters ;ire used in all cases for 




the reinforcement. The decking, par.i|X-ts, water towers, etc., in connection with 
these bridsres were also included in the contract. 



6r 



NEW WORKS IN CONCRETE 



rCSNCRETEl 



REINFORCED CONCRETE BRIDGE AT NORWICH. 

The illustration we show is of a reinforced concrete bridge across the River Wensum 
recently erected by the Norwich Corporation, Mr. -Arthur E. Collins, M.Inst.C.E., City- 
Engineer, supervising- the work. 

The new Dolphin Bridge, which was formally ojjened by the Mayor of Norwich 
recently, is in substitution for the old ferry and path and forms a considerable improve- 
ment upon the lines of the previous path leading froni the river at this point. 

The work had to be prepared as far as practicable in the winter time, and in order 
to obtain a fair appearance the visible portions were cast as slabs or in other convenient 
forms and used instead of boards against which to mould the in situ work. The 
slabs forming the spandrills and outer sides of parapets were moulded face downwards 
on mould boards provided with the reverse of the diaper pattern showing in the 
illustration. .As soon as the concrete would stand firmly the slabs were removed 
from the moulds and scrubbed with stiff brushes and water to remove the cement 
from the surface, leaving the white quartz gravel and sand showing, and forming a 
somewhat rough surface much like cut stone. The general appearance of the work 
is much like dressed granite. 

The slabs referred to have j-in. wire reinforcements, and at most intersections 
of the wires there are ties of 20-gauge wire, the tails of these ties projecting well 
through the backs of the slabs and eventually being embedded in the in situ reinforced 
concrete when the latter is filled in. The visible surfaces of the arches were moulded 
in separate pieces and scrubbed similarly to the spandrils, placed on centres, and the 
concrete was then filled in. 




Reinforced Concrete Bridge over the River Wensum at No 



t-N<UNt.tJ<INCi ^J 



RlilSrORCFJ) COSCRHTI-: RAILWAY SLHHPIiRS. 



NEW USES FOR CONCRETE 

AT HOME AND ABROAD. 

Under this heading retubte information •will be presented as to ne-w uses to 'which concrete 
and reinforced concrete are put, "with data as to experience obtained during the experimental 
stage of such ne^w applications of these materials. The use of reinforced concrete as a 
substitute for timber in exposed positions is one of the questions of the moment, Railtvay 
sleepers, telegraph posts, fence posts, etc. , of concrete are being tried. Similarly, efforts 
are at present being made to pro've that reinforced concrete is an excellent substitute for 
brickwork, inhere structures of great height are required, — ED. 




Fig. 1. Improvkd Frstk 



REINFORCED CONCRETE RAILWAY SLEEPERS IN GERMANY. 

W'e liave from lime to time dealt with the advantages of reinforced concrete for railway 
.sleepers, giving particulars and illustrations of those used in America, Italy, and 
Denmark, and we are now glad to record an 
instance where they are exix-cted to do good 
service in (iermany. 

In that country timber is as yet not very 
scarce nor is iron very expensive, and thus 
wooden sle<>[)ers or the metal " tie " might 
be expected to hold their own for a con- 
siderable period. Nevertheless ex])eriments 
are l)eing made in ditTerent parts of (ier- 
m;iny, notably in Saxony, where the railway 
.'uithorities have just laid down a mile of 
tracU in which reinforced concrete railw.iv 
sleejx^rs have been used. 

The new sleeper has been verv fullv 
described in our (ierman contemporary, 
Bctoii uitd Eiscii, and by the kindness of the 
engineers in charge of the work we are able 
to reproduce some. photographs which have 
not previously been published. 

In this instance, however, the circum- 
stances are somewhat peculiar, as the track 
in question is for a street raihvav, and the 
conditions under which the track is required 
to do duty m.-die the application of rein- 
forced concrete very appropriate, as it is well 
known that the wooden sleeper decays all 
too rapidly in street railway work, and 
owing to the great amount of vibration lav- 
ing the rails on a concrete bed has consider- 
.ible disadvantages. 

The line in question lies between Dres- 
den and Kotzschenbroda, and was put down 
in two sections, 900 yards last year and Soo 
y.irds this year, under Mr. Kopcko and .Mr. 
BIoss, engineers of the Saxon Public Works 
Department. 

The reinforced concrete sleeper used 
was designed on the Italian model, but is 
somewhat simpler than the latter, and 
difTers chiefly in the arrangement of stirrups 
between the top and bottom reinforcement. 
These stirrups are U-shaped, and are 
arranged in the section of the slee|>er where 





H|^iy^ 




^^p* 




^j^^p^i 


^^^M:^^^tltm 



6; 



NEW USES FOR CONCRETE. 



[CDNCRETEJ 



the sliearing stress is at a anaximuni. The wotxlen blucks iiitciuleil In receive the 
screws do not reach to the bottom of the sleeper, but are only 4 in. deep, so as to be 
protected from moisture risinfj out of the ground. This also has the advantage of 
allowing the bottom reinforcing rods to be laid straight without being bent or curved 
to pass round the \\inid<'n blucks, and the part of the sleeper under the rail, where 

Tests after 51 da' s. 




bending moments are most serious, does not require any openings. The holes for the 
woiiden blocks begin near the neutral axis and the tensile stresses on the lower part 
of the sleeper are more favourably distributed. It has been proved by experience that 
4 in. is sufficient for the wooden blocks. 

The sleepers are 2 yds. long and weigh 2og lb. each, 105 lb. being the weiglit of 
the reinforcement. 



66 



r/'ytNoSS'ii^-J /?/?/A7-"0/?C/i/J CONCRETE RAILWAY SLEEI^ERS. 

Tlu- iciiHTiir i-. ci.in|«)M(l (if I |):ir( i)f ccmonl Id 2^ of s;in(l and fint'Iy broken 
slonr. A lilmk ol dak ; in, liii;li i-. inserted liel\\<-en tile sk'ejK'r and the rail in order 



Fh, 4. KuNKORctD Concrete Sleei-ers. 
Views showing part of line from Dresden to Kotischenbroda 



NEW USES FOR CONCRETE. 



ICDMiaETEi 



Jl 






L33 l2of^ I 
LOAD* 



to make the top of the sleeper level with the roadway. This hUx;k has also the 
advantage, owing to its elasticity, of distributing the pressure over a larger surface of 
the sleeper. 

The rails are fastened to the sleepers by 7 in. screws. PiT 
The new sleepers to be laid down this year have an improved 
fastening, which is seen in Fig. i. Clamps 2'4 in. long 
hold the foot of the rail. 

Two sets of tests of these sleejx'rs were under- 
taken by the firm of Dyckerhoff & Widmann, at Cosse- 
baude, near Dresden, one series of tests after the 
sleepers had been allowed to set for 51 days, and the 
other after 237 days. With the load applied as at Showisi, Aii-licahon of Load. 
No. 2 in Fig. 5, it is noticed that in the first set of tests destruction was caused by 
sheer, while in the second set it was caused by tensile stress (see Fig. 3). The power 
of resistance was much higher with the second load (see Fig. 5), being nearly 25 times 
as much, but the setting time did not make much difference, the results only being 
slightlv better in the 237 days as compared with the 51 davs. 

The test proved that the sleepers are of nearly the same strength throughout their 
length. 

The further introduction of reinforced concrete slee|x>rs will naturallv de[)end on the 
time these sleepers last. In spite of the fact that at the time of writing that part of the 
track where the reinforced concrete sleejjers have been longest in service has only been 
laid down a little over a year, yet it promises to give the same favourable results in the 
future. The road was broken up lately in some parts to examine the sleepers, and they 
were found to be perfectly intact. The screws are quite tight, and no corrosion was 
IXTceptible on the rails. 



ELEVATION & LONGITUDINAL SECTION 

k 500 




68 



MHMORAM) 




A'ew Promenade at Margate. — The M.ir^'atc Ccirporation have decided to expend 
ihc suni i>t ^.i[,(>no in eonslriicliii);^ a new sea wall and promenade from Fort 
Point to the Clifton Baths, a distance of 1,050 ft. The promenade will be about 11 ft. 
above hijfh-watcr mark, the heij.jht of the wall beinjj 17 ft. aljove the level of the fore- 
shore. The wall will be constructed of bidl-nosed concrete blocks 4 ft. lonjj, 2 ft. deep, 
and 2 ft. 9 in. thicl<. The top or copinf.^ blocks will be 2 ft. i) in. deep, 4 ft. lonj,', and 
3 ft. deep. The blocks will be comiK)sed of one part of Portland cement to six parts 
uf Brig'htlinj^sea shinsjle, and faced with four parts of Hrightlinffsea ballast to one part 
of Portland cement. There will be altoj.;ether eij.;ht courses of these blocks, backed up 
by concrete laid in situ, and the wall will have a thickness of about 10 ft. at the base 
and about 3 't. at the top. It is pro|x)s;d to make the promenade about 50 ft. or 60 ft. 
in width. 

Reinforced Concrete Warehouse at Monte Video (Uruguay/. — H.M. Lej^.-ilion 
at .Monte \idco h.ivc foru.irded .1 ccip\' of siH-cilicalion, (.'lans, etc., in connection with 
an invitation by the .\dniinistralion of the |«>rt of .\lonle \'ideo for tenders for the con- 
struction of a reinforced concrete w.irehouse on Mole B of the port. Tenders will be 
received up to 3 p.m. on March i6th by the Consejo de .\dministracion del Puerto dc 
Monte Video, Cerrito ni'im. 1.S5, Monte \'ideo. The above-mentioited copy of specifica- 
tions, etc., may be seen by British firms interested on application at the Commercial 
Intelligence Branch of the Board of Trade, 73 Basinijh.ill Street, London, E.C. 

Reinforced Concrete Pier at Brought}- Ferry. — The reconstruction of the pier 
at Br<Hii,'lity 1-frry carried out in reinforced concrete bv Dundee Harbour Trust is now 
completed, and the oniciai tests h.ive proved .satisf.'iclory. The pier is for the landinjj 
of goods .ind [)assent;ers, ;ind the cost of reconstruction' was ;£'2,85o. 

Cmstlewellan Waterworks. — The new- waterworks at Castlewellan, Co. Down, 
have just been finished. Early in February last the first connections were made to 
the main, since which time practicallv the whole town has enjoyed an abundant 
supply of good water. Now that the storage reservoir and filter beds are complete no 
damage as regards either the quantity or quality of the water need be feared. 
The water is stored in a reservoir having a capacity of one and a half million gallons, 
or over 90 days' supply. This reservoir is square, with sloping sides, and is lined 
throughout with concrete; while between the top and bottom layers of concrete is a 
lining of bituminous sheeting. .\ steel gangway, resting at one end on a concrete 
pier, leads to the draw-ofT and scour valves. The filters are in duplicate, the filtering 
media consisting of four feet of stones and sand. A capacious clear water tank adjoins 
the filters, and is covered with a reinforced concrete roof with ventilators. The water 
is admitted to this tank from the filters, and is then drawn ofT to the town by a con- 
trolling valve. Air valves have been placed at all summits, with wash-out valves at 
all hollows, so that the danger of air-lock or block has been provided against. 

Concrete at Parkhurst Prison. — Rapid progress is being m.ade with the building 
of the wall at Parkhurst for the new prison. The wall, which will shortly be finished, 
is constructed of solid blocks of concrete, and is nearly a yard thick and 16 ft. high. 

Teleamouth Sea Defence Works. — The chairman and surveyor to the Teign- 
mouth Urban District Council are inter\-iewing the Local Government Board with 



MEMORAXDA. ICQNQ3ETEI 

regard to a loan of £^1,900 to carry out further sea defence works at the Point end. 
It is proposed to carry a new wall in concrete from the termination of the 
present contract wall to the groyne constructed by the Teignmouth Harbour Com- 
missioners. The present sea defence contract is now on its way towards completion. 
The whole of the masonry work is finished, and reinforced concrete piles are being 
driven outside the wall to hold in the foundations. 

Concrete Groynes at Hove. — The Town Council have decided that a concrete 
groyne and two timber groynes shall be constructed for the foreshore opposite King's 
Esplanade, between Brunswick Lawns and Mill's Terrace, at an estimated cost of 
^^2,784. Tenders are to be invited. 

Concrete for Sewage Works. — .\ contract for a scheme of main sewerage of 
Bentley Colliery and Kostall, Doncaster, h.is been let to Messrs. C. Bushby and Sons, 
of Leeds. The work, which has been designed by Messrs. D. Balfour & Son, of 
Newcastle-on-Tyne, consists in the laying of the whole of the sewers of cast iron pipes 
on a concrete bed, which is necessary owing to the treacherous nature of the subsoil. 
A pumping station is to be constructed of concrete, each of the storage tanks having a 
capacity of 2,000 gallons, from which the sewage will be automatically pumped by 
centrifugal pumps driven by electric motors. Floats are to be provided in the tanks 
so that when full of sewage the motors will t>e automatically switched on, the power 
for which is to be obt.ained from Bentley Colliery [>ower station. The sewage is to be 
delivered at the existing disi>osal works, which are of sulTicient size to take the increased 
quantity. 

Egremont Ferry Pier. — The Wallasey Urban District Council have three piers 
and landing stages for dealing with the cross-river traffic to and from Liverpool — at 
Seacombe, Egremont and New Brighton. The Egremont pier was built about 30 
years ago, and as it was found to be in a very dilapidated and unsafe condition, the 
council decided to replace it with a new and more convenient structure. 

The old structure consisted of a high-level pier, 2S0 ft. long, with a low-level 
stage which was drawn up and down the slipway by hvdraulic ix>wer as the tide rose 
and fell, the high-level pier and travelling stage being connected with a movable 
bridge. The whole of this arrangement has now been removed with the exception of 
eight shore spans, which have been practically rebuilt. The new structure has a high- 
level pier about 700 ft. long and 18 ft. wide inside the handrails; from the river end of 
the pier is attached a bridge 150 ft. long, the river end of which rests upon a floating 
stage 150 ft. long by 50 ft. wide. 

The cast iron piles carrying the girders are all filled with reinforced concrete, 
and the deck of the pier is also of reinforced concrete. The kelsons of the landing 
stage are of the open braced web type, all parts being accessible for painting. The 
pontoons are of wrought iron strongly framed, and fitted with all necessary man-holes, 
pump-holes, and soimding-holes, the inside bottom being filled with cement concrete 
to the height of the floors. 

The cost of the works in connection with the reconstruction was about ;^i8,ooo. 
The contractors for the work were Messrs. .•\lexander Findlay & Co., of Motherwell. 

Density of Concrete. — To determine concrete proportions for greatest density 
Mr. -Albert Moyer, according to the Journal of Gas Lighting, suggests experiments 
with a receptacle holding 4 cub. ft., as, for example, a 15-in. sewer pipe. By using 
two or three sizes of crushed stone properly proportioned a denser concrete may be 
obtained, and cement and sand saved. If there are two sizes of stone, one passing a 
li-in. and the other a f-in. ring, the latter should be screened to remove all that will 
pass a j-in. screen, regarding this as sand. Then 2 cub. ft. of the smaller and a like 
quantity of the larger stone are well mixed and put into the pipe, and the top of the 
mixture marked on the side. .-X mixture of 23 cub. ft. of the larger stone and li cub. ft. 
of the smaller stone, and a number of other proportions, are then tried, and the one 
giving the least volume will give the densest and strongest concrete with the least 
sand and cement. 

Reinforced Concrete In Fire. — .An interesting report on the fire-resisting qualities 
of reinforced concrete has just been made by an adjuster for an insurance agency 
in Chicago. A building of this construction at South Elgin, Illinois, used for the 
manufacture of drugs, was recently subjected to such a fire that a total loss was 
claimed. It was contended by the adjusters that the concrete floors and ceiling were 

70 



l&gyjff^i;.^-:^ mi: MORAS DA. 

not sLillicicnily damaK'c-<l lo warrant lluir (kiiK.lilion, l.iit tlu- owner claimed that the 
concrete had Ix-en weakened by the intense heat, about (.0,000 lb. of drufrs havinjr been 
consumed. It was llnally decided lo test the buildint; bv putting a wei^;ht of 400 lb to 
the square foot on the panels, and it was agreed th.-.t thev should be held defective if 
they deflected more than three-sixt<-<>nths of an inch, that having been the oriirinal test 
made by the architects when the buildin;; was turned over to the owners. Tests were 
made of eipht panels involved in the fire, and all of them showed considerablv more 
than three-si.xteenlhs of an inch deflection when onlv 250 lb. to the square foot 
had t)een placed upon them. The same weifiht was applied to other panels of the 
bmldin« not affected by the fire, and the deflection was shown to be less than one-tenth 
of an inch. .\s a result of the test a total loss was allowed on six panels and a com- 
promise effected on two panels. It was held bv the adjusters that had the building 
been of any other construction than concrete it would have been totallv destrovcd 
on account of the ^'reat heat engendered by the burning' of the drugs and chemicals. 
Ihe conclusion reached was that the weakening of the concrete was caused by the 
expansion of the steel reinforcement under the intense heat. 

Bonding New Concrete to Old. - Mr. Albert Moyer, Assoc. Am.Soc.C.E gives 
the following method <,f bonding new concrete to old :-Clean off with clear water and 
stiff broom the surface of the old concrete. .Mix one part commercial muriatic acid 
or hydrocloric acid and three parts water, or use bonsit or ransonite, mixed according 
to directions with hot water, make several applications one after another with a brush 
containing little or no metal. This will not injure the concrete as the acid does dot 
sink to a suflicient depth before it is neutralised. This will have the effect of removing 
the cement from the top surface of each grain of sand or piece of stone and the other 
aggregates that may have been used, exposing the clean surface of these aggregates 
in exactly the .>^ame condition as they were before being mixed. .After applying the acid 
wash the surface with clear water, scrubbing with a stiff br(K>m or brush, removing all 
the dead particles. While the surface is still wet (and it should be thoroughlv wet) 
apply the new concrete. Protect this new concrete bv keeping it damp for at least a 
week. Do not let it dry out at any time during the first week. It will be found that 
the new concrete will bond to the old as stronglv as if both had been mixed at the same 



time 



.Another method of bonding new concrete to old was recentiv described bv Mr 
1-rank Barber, of Toronto, in the Caiiadia,, Eiij^meer. which consists in placing bags 
of cracked ice on the last surfaces of concrete placed at night, thus reducing the tem- 
perature of the concrete, and, consequentiv, retarding its time of setting, so that on 
the next morning the surface is still plastic, and the concrete then placed will set in one 
mass with the old. The invention of this scheme is credited to .Mr. (). L. Hicks, when 
he was contractor for a reinforced concrete truss bridge in Ontario. .As all of the 
members in these trusses were of relativelv small cross section the ice bags were easilv 
placed in position at the end of a dav's work, and it is stated that the method worketl 
very successfully. To what extent it could be applied to heavier work is not as vet 
known. 

Coke and Stone for Concrete.— Some interesting comparisons of the respective 
merits of coke breeze and stone for utilisation in concrete have been made bv the 
engineer of a coal and coke company in Elkhorn, Mrginia. In order to obtain the 
figures in connection with the coke breeze some small columns, S in. in diameter and 
30 in. long, were made for employment as props in mines. The breeze weighed 27 lb. 
per cub. ft., the specific gravity was 0-005, the percentage of voids was 49-28, and the 
water absorption was 3o-<) [«-r cent. Ordinary qualities of cement and sand appear 
to have been used, the mixtures of cement,' sand, and breeze, four in all, being 
respectively 1-2-3, 1-2-4. 1-2A-5. ^"^ '-3-''- The results of the tests were obtained with 
a Riehle 400,000-lb. machine, the deformations being read from micrometers. With 
one exception the initial loads were 1,000 lb. with increments of 5,000 lb. The results 
showed that the average breaking load of three columns made with the first mixture 
was 85,567 lb., with the second mixture 88,167 lb., third mixture 79,334 lb., and fourth 
mixture 59,750 lb. The average unit strength in lb. per sq. in. in each case was 1,699 
'•752. 1.576. and 1,187. The figures for the stone concrete were obtained from Professor 
E. J. McCaustland at Ithaca. In this case the mixtures were 1-2-3, 1-1-4. 1-2-1. and 
1-3-5. '"ind the average breaking hxads respectively were 151,000 lb., 122,200 "lb., 128,000 lb., 
and 120,933 'b., th^- pverage unit strength being 1,872, 1,472, 1,483, and 1.504. 

C2 7, 



MEMORANDA. [CONCRETE ] 

Although attention is drawn to the facts that iron and steel rapidl\ cornxk- whrn in 
contact with wet coke, and that the coke itself is likely to disintegrate, the coke 
breeze concrete is held to have demonstrated its suitability, except under water, for all 
cases where stone concrete is used, especially as it is much lighter. — Tniics Engineering 
Supplement. 

CATALOGUES. ETC. 

The Combined Coacrete Coastruction Co., Ltd., 41 Finsbury Pavement, B.C., 
have sent us a copy of their new catalogue indicating their various systems of construc- 
tion. We must congratulate the company upon the unique character of this production, 
which is excellently got up and printed, a very special feature being the hand-coloured 
drawings which are shown on separate sheets facing the letterpress of each page. 
.Among the various specialities described and illustrated may be mentioned reinforced 
concrete and hollow tile roofs, reinforced concrete tubular floors, " dry system " (no 
centering), patent reinforced hollow tile fireproof floors, and bridle suspended reinforced 
concrete fireproof floors. The last-named consists of British steel tees suspended in 
patent bridles over the top flanges of steel joists and main girders, or resting on wall 
bearings. The " Bridles " in which the tees are suspended are made from various 
sizes of round steel rods of sufficient thickness to support the slab or beam. In bridle- 
suspended floors the sides of the rolled steel joists or girders are completely encased in 
concrete, the underside being covered with reinforced concrete fixed to lower flange. 
The patent bridle is claimed to be of great advantage in case of fire, and also to bind 
the several floor slabs together. This catalogue will be a useful and ornamental 
.uldition to anv technical library. 

CONTRACTS. 

Messrs. Edmond Colgaet, Ltd., Victoria Street, S.W. — .Among the structures 
which this lirm have at present in course i>f erection ;ire the following : — Money Order 
Department for H.M. Office of Works, Holloway ; new Joiners' .Shop for the .Admiralty, 
at Portsmouth ; Factory at Bailiff Bridge, near Leeds ; new premises at Infirmary .Street, 
Leeds; new Kingsdown Schools, Bristol; new schools, Tiverton, Devon; Newport Road 
Intermediate School for Boys, Cardiff; new premises for Grossmith & Son, Paternoster 
Square, London; .Administration Block, Cottages, etc., at Kinlochleven ; Foundations 
for Fulham Temperance Billiard Hall ; Public Buildings and King's House at Kingston, 
Jamaica; F"loors for Victoria Works, Leeds; Livingstone Hospital at Dartford, Kent; 
Bridges at Saltley, over River Rea, Birmingham. 

J. A W. Stewart, Belfast, have recently secured the contract for the construction 
of new sedimentation tanks, which has been placed by the Belfast County Borough 
Improvement Committee in connection with main drainage purification works. The 
new tanks will be of reinforced concrete, carried on a pile foundation, and will have a 
capacity of 3,000,000 gallons. 

Messrs. Stuart's Oranollthlc Co., Ltd., have recently entered into contracts for the following works : 
Metal and munitions factory, Birmingham; German Y.M.C.A. Buildings, City Road, E.C. ; residential 
flats, Southport ; maltings, Ipswich ; High School for Girls. Barnsley ; Surrey Reservoir, Polesden 
Lacey ; confectionery factories, Stockport ; new buildings, Paternoster Square (Coignet system) ; 
N'orth British and Mercantile Insurance Buildings Waterloo Place, London ; Oleo factory extensions. 
Barking ; Horbury Bridge Mills, Dewsbury ; Buttershaw schools, Bradford ; Queen's High Cliffe 
Hotel. Margate ; bacon factory, Bristol ; reservoir, Drynham, Surrey ; factories for British Drug Housps. 
Ltd., Graham Street, E.C. ; Doulton Road School, Cradley Heath ; engineers' shops, L.B. & S.C. 
Railway, Brighton ; Y.M.C.A. Buildings, Blackburn ; jam factory, Ely ; St. Benedict's Church, Bir- 
mingham, domes, roofs, and arches ; Westminster Mansions, Old Queen Street, S.W. ; London 5: South 
Western Bank, Aldgate, E. ; silos and granaries, Hull (second contract) ; Royal Hospital, Sheffield ; 
Moore & Robson's Brewery, Hull ; garage, Wimbledon ; seed silos and warehouse, Selby ; Henley's 
Telegraph Factory, Woolwich ; silk factory, Coventry ; pumping station, Epping ; new factories, 
engine house, etc., Hayes ; biscuit works, Willesden ; racecourse stands, Kahn system, Mulling.ir ; 
St. Anne's Church, Buxton ; furniture depositories, Shrewsbury ; reconstruction Freemasons' Tavern, 
London ; High School for Girls, Bridlington ; oifices, Dartmouth Street, S.W. ; school for local authority, 
Tamworth ; Upper Wyche Church, Malvern ; silk mills and factories, Flint ; bridges. Ward, End Park 
Birmingham ; navigation mills, Blackburn ; Victoria Institute, Worcester ; bakery, Worcester ; Town 
Hall extensions, Leicester ; reservoir, Wallingford ; Hippodrome Theatre of Varieties, Preston ; Queen's 
Hotel and Mansions, Margate ; stables and offices, Beaumaris Street, Liverpool. 
CORRECTION. 

In the article on "Concrete Tubes as Sewer Pipes" in our December issue the diameter of the 
pipes supplied by the Imperial Stone Co., Ltd., was given in error. This Company manufacture 
concrete pipes from 15 ins. to 48 ins. diameter. 
72 




Hi"' 




CONCKETE 

AND 

CONCTEUCriONAL ETVGrNEEKING 



X'olunie V. Xo. 2. 1,<immi\, Fi:i;iu akv, 1910. 

EDITORIAL NOTES. 



REINFORCED CONCRETE IN THE METROPOLIS. 

ALL iiiterostod hi ivintcnid <(innete :\w aiixioiislx' awaiting the impending 
issue of the (haft regnlalions lor that material which are tu lie 
]irepared under the London Huikhng Act as amended last year, and it 
i.-> lu he hoped that e\-ery possible effort will be made to accelerate the prepara- 
tion i>f this draft, seeing that even when it is complete the procedure to be 
adopted before the regulations can linally come ivito force is almost sure to be 
a length}' one, for the\' have to be referred not only to the Local Government 
Board but also to various technical s'>cieties for review. 

The matter is not only :>f im])ortance to the metro|iolis and those who 
attend to buildings in the county area, but to the whole coimtry. for we may 
lie sure that whatever is finally adopted for London will practically serve as a 
model for many other large centres, and will also be a giiide for the rural 'listricts. 
In two directions we think that something might be done in these pro- 
posed regulations to assist in a general standarilisation of the practice of rein- 
forced concret(\ In the first place, we think that, whatever may be the standard 
algebraict'l notation tinally recommended by the Concrete Institute, this notation 
should be adopted as far as jiossible for calculations required under the new 
re.giilations : secondly, we think there should be very precise instructions as 
to drawings, the manner in which they are to be ,])re|"iared, how they are to be 
figured and annotated, etc., so that we may practically obtain some standard 
nu'thod in the preparation of reinforced concrete drawings, in respect to which 
there is murb confusion at the pi'esent moment. 

REINFORCED CONCRETE CHIMNEYS. 

The Concrete Institute dex-oted its January meeting to the consideration of 
a paper on reirrtorced concrete chimneys, and we give a lengthy summary of 
the paper and discussion under " Recent Views " in this issue. 

The subject is one that claims more attention than it has so far received. 
It was, of course, regrettable that those specialist designers of reinforced concrete 
( liimneys who came o\-er from America met with so little success in this country, 
and had to discontinue their work here owing to lack of support, for during 
tlie short period in which they were in ojieration the chimneys that were erected 
under their supervision were certain!}' of a satisfactory character. The rein- 
forced concrete chimney is essentialh- economical where large chimne5-s_have to 
be erected and where there is little space for their foiuidations. 

73 



STANDARD DRAWINGS. 1CQNCBETE3 

It is a matter that some of our leading builders and also some of the rein- 
forced concrete specialists would do well to look into, for the moment our 
industries begin to look >ip tliere will be a larf:;e field for chimneys of this descrip- 
tion. 

STANDARD DRAWINGS. 

I\ our last issue we dealt '.\ith tlie question of standard notation as suggested 
by the Concrete Institute. !n this number we publish an article on the stan- 
dardisation of drawiiiiiS. 

We. who see so m.iny drawings of rciulnrced concrete work ])repared 
both by members of ihe technical professions and by specialist designers, are 
somewhat surprised at times at the extraordinar)' divergence in the practice 
adopted in preparing the necessary sheets. There is great confusion among 
the professions on this point. In many cases much unnecessary drawing is done, 
and there is no similarity in the character of the figuring or description of the work. 

A great saving of time and labour would be effected, and it would be a boon. 
indeed, tci all concerned, and ]x;rticularly to those who supervise the execution 
(it Imildings. if a standard, lorm of drawings were eventually adopted. We 
are glad to note that one nf the Standing Committees of the Concrete Institute is 
taking up this matter, and we trust that they will arrive at a satisfactory solution 
of the jiroblem. 

CONCRETE AS A FIRE RESISTANT. 

The recent fires in dra[)ery stores should reminrl architects of the absolute 
necessity of protecting all steel work with concrete, no matter whether this 
covering be laid down in the local regulations or not. 

Unprotected steel-work is very dangerous, but if iiroperly protected it is a 
safeguard of the highest order. Under the London Building Act Amendments of 
icjOO the protection of steelwork has been ordered for certain classes of buildings, 
and it is to be hoped that eventually this requirement will become a general 
one. There is no doubt that in buildings of the type affected by the fires 
named the protection of the steelwork would ha\"e meant a considerable 
reduction in the loss of life and property. 

Building owners should not oveidook the ad\-antage of the use of reinforced 
concrete, and it was particularly noticed that the conrrete parts of the two 
stores recently burnt down offered much greater resistance to the fire in each 
instance than the ordinary brickwork. 

In the case of the fire at Messrs. Arding & Hohbs the Inspector of Factories 
emphasised the fact, upon examination, that the concrete staircases stood very 
well, and that they were stiil quite firm, whilst the District Surveyor in his 
evidence gave it as his opinion that " had there been concrete floors, and had 
the ironwork been encased in cement, the goods only would have takenfire, 
and the fire would soon have been put out." 

Directly the new huildin.g regulations referred to above have been decided 
upon there can be no doubt that clear-sighted owners of large enterprises will 
make a grea^ter use of this material than heretofore. 



7+ 



NEW ROYAL AUTOMOlil LI-: CLUii. 




CONCRETE AND REINFORCED 

CONCRETE AT THE ROYAL 

AUTOMOBILE CLUB'S NEW 

BUILDING. 



/•I '.;,"7;- of the •.rnrorljnci- of the ne%u premises rwtv being erected in Pall Mail for the 
Royjt Automobile Club, tve intend presenting a series of jrticles on this structure. The 
present one deals principally v>lth the tvork in its initial stage. Later on ive shall give 
particulars of the building "when it is more adiianced, finally describing the finished 
structure. These articles are being prepared for us by Mr. Albert Lakeman, Hon. Medallist 
Construction, Lecturer at the Wooltvich Polytechnic. — £D. 



Tin; im])oitaiU buildiiig lunv being cTccU'il m Pall .Mall as the new club huuse 
for the Royal Automobile Club, contains many interesting forms of construction, 
one of the chief features being the concrete and reinforced concrete work. 

The site, 228 ft. by 140 ft., is that formerly occujiied by the old War Office 
buildings, with a frontage to Pall Hall, while the rear adjoins the Carlton Gardens. 

The new building which is being erected from designs by Messrs. Mewes & 
Da\is antl Mr. E. Keynes Purchase (the joint architects), will have eight floors in 
all, inchuling two floors which come below the pavement level. The retaining 
wall at the rear of the building, ne.xt the Carlton Gardens, is constructed in 
reinforced concret-e, and a few details of its ctmstruction should prove interesting. 

The total length is about 200 ft., and the height, which varies, is roughly 
about 3t ft. The soil which it had to support, being loose gravel with a great 
tendency to slide, required \-ery careful shoring during the e.xecution of the 
work, and ])articularly as the bottom of the wall' in some cases comes below the 
surface water level. Some idea of the elaborate strutting that was required can 
be gathered from the illustration (Fig. 2) which also depicts a portion of the 
site at the rear, and some of the trenches required for the grillage foundation 
can be seen at this point forming as they do a very large excavation. 

In designing the wall, very little projection was possible on the side next 
lo the gardens, and consequently a small heel projecting only 2 ft. 6 in. was 
formed, whilst the toe projects under the new building to the extent of over 
12 ft. in some cases. One of the chief difficulties occurred ne.xt the swimming 
bath, which is being constructed in the basement, as it was necessary to erect 
the retaining wall in the first instance, and carry out the excavation for the 
bath at a later date. Owing to the depth required for the bath, this excavatioa 
came below the bottom of the reinforced wall, and it was necessary to take great 
precautions to prevent the possibility of any sliding, especially as the work was 



75 



REINFORCED CONCRETE. 



ICQNCBETEJ 



well below the surface water lewl. The line of e.xcavatMn is shown on the 
drawings of this wall (Fig. 2), and it will be noticed that the actual foundation 
to the wall was carried down to the le\-el of exrax'ation required for the "bath, 




and a large mass of 12 to i jilain concrete filling employed to form a firm base 
to the wall and obviate any movement taking place when the surrounding soil 
was removed. At all other portions of the wall the foundation is simply formed 

-6 



k-SoSS'iii?^-] Nl-W ROYAL AUrOMUBILI- CLUB. 

with !_' 111. (.1 comciit coiidvtr. m onlcr that the asphalt daiiip course could 
lie apjihed. and upon this the base ot the wall is directly carried. This asphalt 
damp course is worth\- ot note, l-.einj,' continuous under the whole building and 
|>assint; imdei all walls, grillages, and Moors, as can be seen from the drawings. 
Ihe tluckiiess employed was J in. under all floors, and fin. under walls and 
grillages and in vertical positions. Brick walls were built where necessary for 
the application of the vertical layers as shown. 

/•;,!,'. ,5 is an interesting one, which shows the foundation to the reinforced 
wall after it had been prepared and asphalted, and although the full length of 
the wall is not shown. st)me idea of the size can be gathered. The stepped jwrtions 
lorni an excellent abutment for the base of the wall, and ])revent any sliding on 
the asphalt, and this was particularly necessary where adjoining the swimming 
bath. The actual height and section of the wall \-aries at different points, there 
being practically three different heights, tw<, (,f which are illustrated in the 
drawings, and the third is 2 ft. less than that which was required near the 
swimming bath. 

In all cases the wall has a vertical lace ne.xt to the gardens and a battering 
face towards the new building. The thickness of the wall at the base next the 
plunge bath (where the greatest height was required), is 3 ft. 6 in., and it tapers 
to ij.l in. at the top. The thickness of the heel varies from 4 ft. to 5 ft. (> in., 
w liile the toe is diminished as shown. 

The concrete employed was conijiosed of good ballast and Portland cement 
111 the proportion of i and 5. the whole being mixed by machinery and well 
rammed in position. The reinforcement is [M-ovided by indented steel bars of 
:.' 111. and i\ in. section spaced at distances, horizontally and vertically, varying 
Ironi () in. to 24 in. centre to centre, and the \-ertical bars in the wall are carried 
into the heel and toe in different forms as shown. Some of 'these bars were of 
such a length and shape that it was found impossible to cart them to the site 
m the shape required, and they wwe consequently sent to the building and after- 
wards formed to the various curves by bending in a hydraulic press, three bars 
being operated upon at a time. The shuttering for the back of the wall and the 
nu'thod of spacing the ivinlorcc'inent can he seen in Fig. 2, where some of the 
N-eitical bars are seen in position. The horizontal notched timber was fixed to 
allow a covering of 2 in. to the main reinforcing bars, and small pieces of brick 
were placed under the foot of the bars to allow the same thickness of concrete 
at the bottom of the wall. Where it was necessary to join bars that were 
continuous, as in the case of the horizontal reinforcement, the bars were made 
to overlap and a splice formed 6 ft. long. 

Although not necessary for purposes of strength, all vertical and horizontal 
bars were wired together where crossing one another, before any concrete was 
filled m. the object being to prevent any possible displacement of the reinforce- 
ment, this naturally being a very important matter, and although this systfem 
entailed some 15,000 wirin.gs. it is certainly the best method of executing the 
work. 

-■\fter the wall had dried sufficiently, the shuttering at the back was removed 



REINFORCED CONCRETE. 



[CQNCBETEJ 





, ing timbering for reinforced i 
New Royal Automobile Cllb 



NEW ROYAL A UTUMOIil Lli CLUB. 




79 



REINFORCED CONCRETE. 

Fit;. 4. View of front portion of ^ite. 



[CQNCKETEl 




Fiy. 5. Foundaiion tor reintorced concrete wall. 
New RoYAr, Automobile Club. 



NHW ROYAL AUrOMOIilLB CLUB. 



.111(1 the vfilual asi)liall a|ii)lii'(l to the whole surface before filling in with the 
iz to 1 concrete well lamnHd into jjosition. The comi>leted wall is shown in 

/•fir. I. 

Six weeks were allowed to elajise after the concrete had been jjlaced in 
]r)sition in the wall before the lirst tier of struts was removed. As each strut 
was withdrawn the holes were carefully tilled up with cement concrete, and seven 
days' interval was allowed between the removal of each tier in order that the 
weight coming upon the wall might be gradually apjilied. 




<S>t0^m cr ffeONT BtTAlNiNG WUL ■ 



Fiu 6. Drawinjl of front retaining wall. 
N'ew Rovai, Automobile Ch it. 

The front retaining wall affords an excellent example of plain concrete work, 
and it is very interesting to compare the two walls. This wall extends along the 
whole frontage to Pall ilall, forming the outer wall of the vaults, which come 
under the pavement, and supporting the roadway for a length of 228 ft. and a 
height of nearly 30 ft. As the space in the front vaults was not so valuable as 
that at the rear of the site, it was decided to use plain concrete, although it was 
found necessary to employ a wall with a thickness of 6 ft. at the base. At the 
same time the work could be executed with great rapidity, and this was an 



81 



REINFORCED CONCRETE. 



ICQNCKETEJ 




IZ 



A7-;VV ROYAL AUTOMOBILE CLUB. 



ini|iortaiit lactor iii such a position. The hne ui cxciivation is sliown on the 
(irawing of tiiis wall (/•"/g. 6), and it will be seen that it was necessary 
to hiiikl uj) a ()-in. brick wall for a portion of the height in order to apply the 
\ertical asphalt damp course on the outside of the retaining wall. There are 
two offsets at the hack of the wall ne.xt the roadway which reduce the wall 
from 6 ft. at the base to 5 ft., and 2 ft. 6 in. respectively. There is also one 
offset of () in. inside the vaults, this break occurring at the floor level wherever 
the lower ground floor is carried through into the vaults. There is no heel to the 
wall, but only a short toe which projects about 2 ft. ') in. under the vault floor, 
riu' concrete used in this wall was composed of good ballast and Portland cement 
111 the proportion of (\ to i. It is interesting to note that ,50.550 cu. ft. of concrete 




were required for the construction of this wall alone. The greatest care had to 
be exercised in supporting the numerous mains that came in close proximity 
to the work, and the shoring required was of the most elaborate character. A 
portion of the finished wall can be seen in Fig. 8, and some of the timbering 
is also shown. The sloping roof to the vaults, shown on the drawing, was con- 
structed of rolled steel joists and concrete. A portion of the underpinning to 
the w^alls of the Carlton Club (which adjoins the new building on the east side) 
can be seen in Fig. 8, and this work involved a great amount of material and 
labour. The thickness of the walls that were underpinned, in some cases reached 
as much as 6 ft., and the width of the concrete bed required luider the new and 
old walls was 21 ft. in some instances. 

83 



REINFORCED CONCRETE. [CONagEJE] 

There are several other retaining walls of more or less importance, and they 
were all constructed of plain concrete. The largest of these are the walls 
forming the special chamber constructed below the basement floor to contain 
the ejectors which will be employed to raise the sewage. The size of this chamber 
is 15 ft. 9 in. by II ft. in the clear, and the depth over 20 ft. below the basement 
floor level. The greater portion of this work being below the surface water level, 
gi-eat care was necessary during its execution, and steel piling was employed in 
place of the usual timbering to support the sides of the excavation, which was 
;io ft. by 23 ft. in area, and nearly 30 ft. in depth, previous to the retaining walls 
being put in. These walls are 6 ft. thick at the base, and diminished by two 
offsets on the outside to 4 ft. 6 in. and 2 ft. 3 in. respectively. They were built, 
m all other respects, in a similar manner to the main front retaining wall. It is 
also rather interesting to note that in several cases the manholes below the 
basement floor were of such a depth that it became necessary to calculate the 
walls as retaining walls, and it was found necessary, in some instances, to make 
them 3 ft. 6 in. thick at the base. These were also executed in plain cement 
concrete. 

A general foundation plan is shown in Fig. 7, and the numerous grillages 
required under the stanchions can be seen ; also the positions and length of the 
retaining walls above described. The figures in the circles are merely the 
reference numbers for the various stanchions. 

Messrs. TroUope Colls & Sons, of Pimlico, were the contractors for this 
work, while Mr. S. Bylander was the consulting engineer to the architects. 

The indented bars were provided b}' the Patent Indented Steel Bar Co. 
Ltd.. and the Portland cement used was the "Hilton .\nderson " brand of the 
Associated Portland Cement Manufacturers (iQOo) Ltd. 



84 



f J, CON.TI UIKTIONAI.I 
L'v t.M(.INV-l.klN(. ~J 



STAXDARDISATIOX Ol- Dh'.WVISCS. 




1 



STANDARD METHODS FOR 

THE PREPARATION OF 

REINFORCED CONCRETE 

DRAWINGS. 



U) II. K.LMI'TON U'lSON. C.E. 

iTt'clntical Secretary of the Concrete Institute.) 

In 'v.'etv of the great difference vjhich exists among the members of the 'various pro- 
fessions in the manner of preparing drawings, life tfiink something stiotild be done towards 
standardising the metttod for preparing these dra'wmgs, "which "would greatly reduce the 
expense Incurred in the drawing office'and be a boon to alt concerned* This standardisation 
•would also do awav "With the necessity of liawng special dra-wings made for reproduction 
in technical /ournjts and trade catalogues. We are glad to note that the Concrete Institute 
are taking up the matter. —HD. 



The aciv;iiit;i,t(es of sl.-indardis.ilion in all hraiiclits of comnuTce are recojj;nise<i by 
overyonc nowaday?;, and there is a ki't^'''' tendency noticeable towards standardisa- 
lion in many other directions. Theoretically, we nia_\' be able to effect economies in 
the amount of material, and secure a closer a|>i)r<>ximalion towards the true result 
by variety; but we can, by the judicious choice of fairly extensive lists of standards, 
economise both lime and materials, and, thouj.;h we may not always secure theoretical 
elliciency, we .ire en.ablcHl to arrive at a practical result with fj;reater final economy. 

Recently, the Concrete Institute has set itself to standardise the symbols employed 
in making calcidations for reinforced concrete desii^ns, and the attention of one of 
its Committees is now beinjj directed towards the standar(lisation of drawings 
for this system of cfonstruction. This is only one instance of a tendency, which is to 
be noticed more es|}ecially in the I'nited .States, towards some sort of standard methods 
of preparini^ worUintf dr.iwinf^S. Though there is some slight variation in detail in 
the I'nited .Stales in respect to working draw ings for steel work, there is a great deal 
of uniformity to be noted in such drawings as a ride. .This standardisation has resulted 
in a great economy of time in the dr.iwing office ,uid in the works, and the final 
outcome is that, in many br.-mches of steel work, .Xnierican practice has resulted in 
considerable saving over the more elaborate and, perhaps, more theoretical methods 
which h.ave been customary among English and Continental engineers. .Material is 
often .apparently thrown aw.ay, but the economy thereby effected of time and labour 
in other directions more than makes up for the loss. Therefore, we may feel certain 
iliat in standardising the methods for the preparation of reinforced concrete drawings, 
I inbodying both the preliminary schemes and the final working drawings, a good deal 
will have been done towards reducing the great amount of expense incurred in the 
ilrawing offices of specialists. Another effect, too, which the standardising of drawin.^ 
methods has had uix>n structur.-il steel-work pr.actice in the I'nited States will probably 
be seen in connection with reinforced concrete; that is, in co-ordination and con- 
densation from the cli.aotic condition of too much individualism in design, and a better 
understanding of the principles of the subject. 

.Among the i^eneral advantaijes that may be obtained from having the drawings 
prepared throughout in a uniform manner .ire: (il They become more intelligible 
to evervone concerned, so securint,"- .i l>etter uiidersiaiiding and su])erior execuiion. 



REINFORCED CONCRETE. [CONCRETE]) 

(2) This standardisation economises in many direciion.s, sucli as, in saving of time, 
the avoidance of the necessity for mal-cini; special dra\vin.i;s for reproduction in cata- 
logues and in the Press, and, indeed, for reproduction by the various processes 
ertiployed for the copying of drawings, known commonly as blue prints, black-line 
prints, etc. 

To the architect or engineer who has to study the competitive schemes submitted 
by firms of specialists, drawn up in many ways, and which mostly differ in scale, 
their examination and comparison is troublesome and wasteful of time, the result often 
being that some schemes do not receive proper consideration. 

Indeed, the advantages of standardisation are as great in respect to the prepara- 
tion of working drawings as to the manufacture of materials and articles of commerce. 
It may be doubted whether it is yet opjKjrtune to endeavour to standardise systems of 
reinforced concrete and details of such construction, but it is not too soon to endeavour 
to standardise the preparation of working drawings for such work. When such is 
■done, we shall have taken some sie]> on the road towards standardising methods of 
designing reinforced concrete. 

Considering the question of drauing^s for reinforced concrete, we note, lirstlv, 
that these belong 10 two classes of work. In the one case, reinforced concrete is used 
in works of a civil engineering character, while, on the other hand, it is employed in 
general building construction. These two branches are In the hands of two professions, 
namely, that of the Engineer and that of the .\rchitect, each of which 
differs somewh.al in the methods custom.ary at the |)resenl date in respect 
to scales, line-work, .and colouring, i.e., m<'thods of recording ideas and 
specifying requirements. We, iherefore, have lo decide as to whether it 
would be advisable, in drawing up standards for draughtsmen, to lean 
more to one branch th.an lo the oilier, or whether some middle course should be 
pursued or a different road tak;'n. 'I'lie latter would be inadvisable, because it would 
dejjart too much from current practice. .\ middle course is considered the safest, but 
in this case we are inclined to think that regard should be paid to the amount of 
work which i> lo be done in each branch. 

RriiitorcLtl concrete is most extensively used in building construction at the present 
date, .and it is most probable that it will continue there to be used most largely. 
In this it is not wished to imply that the largest works, or works costing in the aggregate 
the most, are executed in this branch of building, but reference is made to the 
number of jobs which are carried out in which reinforced concrete is employed by 
architects and by engineers. It seems to be the case that the most drawings are 
required in connection with the architectural branch of reinforced concrete, and it would 
therefore seem best if the drawings should conform most closely to the general practice 
in the architectural profession. The advisability of this can be considered to be 
strengthened still more by the fact that standards which can be drafted for the pre- 
paration of such drawings for architectural w'ork are not useless or unworkable for 
engineering work. We see that methods which suit the architect are readily legible 
to the engineer, and will not cause him annoyance nor inconvenience in any way, 
■whereas, if the opposite course were pursued, the architect would find the drawings 
entirely strange to him and out of character with those for the remainder of the work. 

SCALES. 

Various specialists and contractors for reinforced concrete work adopt a variety 
of methods in this country in respect to the scales which they employ in draughting. 
It would be too great a task to endeavour to standardise scales for drawings for 
international use, because different nations have different units. This might not be 
considered as excluding the L'nited Slates from our |)ur\iew. but in that country 

86 



[/■.Inoj'nklkIn.':^ STAXDAUDISATION OF DRAWIXGS. 

there are ;ils<) dilfLTiiKos of piarlico antl custom; for instancf, in the Liiited Males 
tliey use Ions of 2,000 11). and llie writer is not suflieiently familiar witli the conditions 
of American practice lo warrant him endeavourinj,' to lay down any standard svslem 
to embrace tliat country; lliat must be left to American enj,'ine<-rs. The writer, how- 
ever, is inclined to tliinl< th.it the reasons which may lead to certain rules bein^ laid 
down for this country will be equally applicable to the Unite<l Slates. 

.\ j,'ie.-it number of sc.iles are, and have been, employed by architects and engineers 
in Great Britain, but only a few are generally adopted; we can use these few lo fulfil 
almost all requirements. Fundamenlally, we choose a scale to suit ihe conditions 
of the extent of the job and the size of the drawing paper, having due regard to 
clearness. We recognise that a l.irge scale is desirable, but, at the same lime, it 
must not be so large as lo be inconvenient in use. We find, therefore, a n.atural 
limitation in the number of sciles that are practically available, because some scales 
are too large, others too small. We find that several scales that, theoretically, have 
been supposed to be advantageous are eliminated from customary use; for instance, a 
jV-in. scale, which is applicable lo decimal equivalents, is too sinall for general use, 
and therefore is seldom adopted by .-irchilecls for jobs of a f.iir size; it is not unwieldv, 
indeed, for very large jobs a smaller scale is adoptwl, the cuslom being to halve the 
i-in. scale and employ .1 iV.-in. scale. The l.itter is quite too small for showing details 
of the reinforcement, but on large jobs it would be satisfactorv for general 
schemes such as plans, elevations, and sections, which do not show the reinforcement. 
The ^-in. scale is still better for such purposes, but both these scales, preferablv the 
latter, become distinctly serviceable in the preparation of sketch-designs and general 
schemes which arc submitted in the preliminary stages of anv job, because thev 
conform to the architect's other drawings, and are therefore comparable. Some 
s|:)ecialists em])loy J-in. scale drawings to show slab reinforcement, and on jobs of 
any magnitude this is a good system, but the lines are then close together, and in repro- 
duction there may be a tendency for these to obscure one another, such as, for instance, 
when the rods are spaced ;is closely as 3 ins. centre lo centre. .\s a rule, however, 
such a close spacing is not adopted, and the whole area of a floor slab can be lined with 
reinforcement and yet be clearly interpretable. Where a closer spacing is necessarv, 
it is possible to mdicate the general character of the reinforcement on a small portion 
of the drawing or 10 put a reference thereon, ;ind provide a detail of a sm.ill portion 
to a larger scale to be re.ad in conjunction therewith. 

The j-in scale is too large for general plans, and is seldom used even for jobs 
of moderate size. Though it would be suitable for showing the reinforcenient of 
Toor slabs, in the same way as .ibove referred to, ,ind, indeed, can be shown much 
more cle.irly, it seems, however, lo Ihe .author, unnecessary because, as a rule, rein- 
forcement of tliis kind can be show 11 sulViciently clearly upon J-in. scale drawings, 
while the j-in. scale is not sufTiciently large for details in elevation and section. 

The s-in. scale is seldom used, but the A-in. scale is often employed by specialist 
engineers for elevations and sections of beams and floor slabs. It is convenient 
in so far as dr;iwings lo this scale do not lake up much room, but the ^-in. scale 
is too small lo enable details of the arrangement of the reinforcement to be shown 
in any l)ut a diagraiiimatic way. A tliagr.am, however, is all ihat is necessary in the 
majorilv of cases, and economy in the drawing otVice is effected by its use, for a 
number of beams can be detailed in ;i small space which, again, is advantageous on 
ihe job, as the foremen and workmen are not h.ampered with large drawings. 
Economy is likewise effected in the number of drawings necessary to show the con- 
struction being reduced to about half of what would otherwise be necessary, i-in. 
scale drawings are, by manv si)ecialist engineers, supplemented by sections and details, 
lo li-in. to i-in. scales. 



REINFORCED CONCRETE. 



[CQNCBETFJ 



The ij-in. scale dots iiol apparL-ntly meet willi favour, lliouj^li it represents 
one-sixteenth full size. 

The i-in. scale seems to he ijeneraljy admitted to be a useful scale, and preferable 
to j-in. It is sufficiently lart^e to conveniently show a fair amount of detail and 
occupies an intermediate position between i-in. ;ind i^-in. scales, but the i-in. scale is 
often too large for detailed drawing's of long beams, and, therefore, though a certain 
number of engineers have employed the i-in. scale for their drawings, as all that is 
necessary can be shown on a i-in. scale drawing, the \\ riter thinks that, notwithstanding 
its clearness and serviceability, it is better not to favotir it. 

The ij-in. scale is one-eighth full size, and provides sufficient size in which to show 
details of construction very clearly. It is useful to remember that i in. to this scale 
represents i in.; so that we can use .in J-in. scale to read inches on i^-in. scale 
drawings. 

The 2-in. scale, so far as the writer is aware, is used onlv bv one hrm of reinforced 
concrete specialists. Though useful for details, it is not a scale which has met with 
any favour, and it seems to be altogether ignori-d by architects. 

The 3-in. scale is one-quarter full size — a handy ratio — and is verv valuable for 
details of s|X'cially intricate work. 

Though architects often use half-full size for details, it is generallv too large for 
reinforced concrete work. 

\\"e see, therefore, that we may bring a considerable number of scales that are 
and have been emi)lo\ed in general pr.-ielice down to ;i few in reinforced concrete work, 
these few being quite sufficient to give considerable latitude. They are : The j-in. 
scale, for general drawings, showing schemes in outline, .and for framing plans, 
showing disposition of beams without reinforcement, and the rods in slabs, both at 
bottom and top. For the g-in. scale ig-'". m^ty be substituted for large jobs, but 
then it is necessary to show the reinforcements in floor-slabs upon j-in. scale drawings. 
.\ 3-in. scale can be used for elevations of beams, etc., .and for general diagrammatic 
drawings. Sections of beams, etc., should be shown to ij-in. scale. For large 
details of intricate work the 3-in. scale will be found useful. Thus we have, generally 
speaking, only three scales in use, namely, the g-in., i-in., and 15-in. 

It mav l)e well to here emphasise the importance of figuring" all dimensions upon the 
pl:uis, and le.aving nothing to be scaled from the drawings. 

HOW TO SHOW THE REINFORCEMENTS.' 

.\s regjirds indicating reinforcements upon plans specialists are somewhat at 
variance. Occasionally we see the bars shown by dotted lines, while the outlines of 
the beams are shown in full lines, and the walls the same. The more general custom, 
however, seems to be to em)>loy full lines for the reinforcements, and to dot the beams. 
This is not quite clear, and it is rather awkward to show walls on the same plans 
where this method is employed. It is suggested, however, that the best method is 
to outline the beams by short dots or strokes, and to dot in with long dash strokes 
the w.iUs. The reinforcements may be shown by heavy lines. On A-in. scale 
drawings the main rods may be shown generally by means of thick, solid lines, 
secondary rods by lines of medium thickness, and the details of the concrete and other 
work again by means of thin lines. When working with this small scale, it will 
be found an advantage often to omit the reinforcements in adjoining members, as, 
for instance, the rods in noor-slabs should be omitted when drawing elevations of 
T-beams, otherwise the main reinforcements may be obscured. 

In lA-in. and 3-in. scale drawings it will generally be found .advisable to show- 
rods, when not of too small a size, by means of double lines. These lines, however, 
should be stronglv drawn. .\s these two latter large scales are generally employed 



f 1, CON>'IUUfl ionaD 
t^ ENGllMtEBlNO — ^J 



STANDARDISATIOX OF DHAWINCS. 



©i 



^ ^ 



//) 



j Jdr-^ 



i^.6- 1300) 



^4if///02) 



® 



^- 



.!^ 



/^ 



fur si'ctions, it ina\- hv here said lliat it loolcs well to blaclv-iii any reinforccnients shown 
ill section. Even on the largest dra\vinH:s- full size, even- it is better to blacU-in 
tlie sections of steel, for the drawings are made nuich clearer thereby, and, thoui,'h 
emphasis is given to' the steel, this is an advantage, as too much emphasis cannot 
be given to the reinforcements, (he drawings being specially intended to indicate them. 
If shading of rods is employed, it should not be done on anvthing less than half- 
full-size drawings. .Sections of beams, etc., will often require picking out, :ind 
elehing is sometimes employed with this object, but the lines in etching should be 
\i-ry open or, otherwise, if ilie drawings .are reproduced .and reduce^d in size by 
photographic me.ins (which may very possibly take place, and should always be 
provided for), any closeh-spaced lines will run together or "clog." .\Ianv draughts- 
men, however, prefer to indicate the concrete by dots, intended to show stones, their 
contention being that etching takes longer to do .and requires great care, for the 
Imes must be spaced with great e.x.actitude .it regular distances apart, otherwise 
the ;ip[>earance of the drawing is not .at all good, 

j ' ; : i 1 BEAMS AND COLUMNS. 

-- - ---~--.-^- '-■-■ As regards llu' recording of beams, columns, etc., 

, -f °/"-^f^ r -. - upon floor ]jlans, it is suggested that the positions of 

I I I i \ '. the reinforcements in the columns need not be indicated 

I ' ' j i ■ upon everv plan. On the larger plans, where the rein- 

' forcements are shown, it is onlv necessarv to indicate the 

Fig. 2. Showing Outlines or , , , ■ , , ' , . ' . . , , 

■ Secondary AND Main Beams. beams .and (lot m tile columns; this omission of the 

89 



REINFORCED CONCRETE. 



ICQNCBETEJ 



rods in the columns results in niakinj; the drawings clearer. On i-in. scale drawings 
the columns mav be blacked in solid. The lines showing the outlines of the secondary 
beams should abut against the outlines of the main beams, as shown in Fig. 2. The 
columns should be detailed as a complete series 
throughout the structure, the connections of the same 
with beams being shown in outline. By this method 
the reinforcement^ can be more conveniently shown. 




^S 



=F^ 



= • 



SffcAe^ /^-x^ 



IS Fio. 3 TO La 



Scale. 




in their pro])er relations to each other without them- 
becoming obscured by the lines of the reinforcement 
in beams. If necessary connections can be shown by 
li-in. an-d 3-in. details. 

INK AND COLOURING. 

.Ml drawings for reinforced concrete should be 
prepared in waterproof black ink, and the lines should 
be strong and solid. It is of the greatest importance 
that these requirements should be obser^-ed where 
there is anv prosi^ect of the drawings being reproduced 
in any shai)e or form at any time. No washes or 
shading should ever be employed, in such cases, 
because the former come out as solid patches by 
ordinarv methods of reproduction, and the latter, 
where the drawings are reproduced in process repro- 
duction, tend to clog up and produce solid patches. 

It is in.advisable to colour drawings for rein- 
forced concrete; even in drawing details of large 
size, i.e., 3-in. scale or half-full size, it is inadvisablr 
to dot in the concrete in any w-ay, for if, as may bi 
possible, these details are reproduced in catalogue^ 
or the Press at any time, the great reduction that 
must occur will cause these closely-spaced marks to 
run together and become clogged, or, perhaps, make 
a solid patch of ink. It is, of course, possible to re- 
produce drawings having colour washes upon them, 
do so the half-tone process must be employed, in which there 
is a screen or meshwork over the surface that breaks up the Imes and 
often renders them indistinct; furthermore, the half-tone process is more expensive 

90 



ffl& 



but 



m 



SrANDARDISATlOX ()!■ I)RA\VI\GS. 



III. Ill ilu- line |ii(icess. l-'iir superior effccl il is most important thai all drawiiif^s shuuld 
!)<• <k)ni.- in IjlacK' and while. Kiirlhermore, this allows of their beinj^ copied by the 
ordinary photo-print process, in which any washes would lead to oljscurity of detail. 
If it be found necessary to employ colours to distinfjuish various parts of the work, 
1(1 it be done upon black-line prints, which are easily and cheaply made from 
drawings; and il may be here irenlioned thai all colours, except lif<ht-blue, by the orili- 
n.iry photof^raphic method of reproduction, come out the s.-ime as ihouj^h they were in 
solid black, in which, therefore, if any wash is employed, where reproduction is 
desired, it must be a very faint blue. 

The following; list of conventional colours used u|X)n archiledural drawings may 
lie found of service where drawing's li.ive to be coloured :-- 



EARTHWORK. 

CONCRETE. 

BRICKWORK. 

STONEWORK. 



SLATE. 

TILICS. 
PLASTER. 
WROUGHT 
IKON. 
CAST n^ON. 

STEEL. 

LEAD. 
BRASS. 
COPPER. 
GLASS AND 
GLAZED WORK. 
WOODWORK. 



CLD WORK. 



Section. 

Burnt umber; if turfed, Hooker's green 
(mixture of Prussian blue and gamboge). 

Neutral tint, mottled. 

Indian red or crimson lake. 

If set in cement, purple and blue. 

If Staffordshire in cement, green. 

For dressings, sepia ; for rough or hard 

stone, indigo ; and for granite, Venetian 

red or indigo, black dotted with pen. 

Green, indigo and yellow ; purple, indigo 

and crimson lake. 

Venetian led antl a little yellow. 

Neutral tint. 

Prussian blue. 



Payne's grey (mixture of indigo, Indian 

ink and crimson lake). 

Purple Imixture of crimson lake and Llitto. 

Prussian blue). 

Indigo. Ditto. 

Gamboge. Ditto. 

Lake with \enetian red. Ditto. 

Mottled cobalt. Ditto. 



Plan and Elevation. 
Not coloured. 

Lighter tint of section 

colour. 

Venetian red or yellow 

ochre. 

Lighter tint of section 

colour. 

Ditto. 

Lighter tints of section 

colours. 

Ditto. 

Ditto. 

Light Prussian blue. 

Lif^ter tint of section 

colour. 

Ditto. 



Pine or fir, unwrought and floors, streaked 

with burnt sienna. 

Wrought pine or fir, burnt sienna. 

Oak, sepia and a tinge of yellow. 

Mahogany, brown madder. 

Walnut, sepia and burnt sienna. 

Black or hatching. 



Raw sienna. 

Lighter tint of section 

Ditto. [colours. 

Ditto. 

Ditto. 

Black or hatching. 



It may be here mentioned also, that tracing cloth or linen is very useful for rein- 
forced concrete drawings ; instead of it being necessary to prepare pencil drawings, and 
then perhaps inking them in before tracing, pencilling can be done direct upon the- 



9' 



REINFORCED CONCRETE. [CQNCBETE] 

tracing' cloth (this [jermits of ready cleaning, rubbing out or erasing by the simple use 
of benzine), and upon the same drawings the pencil lines can be inked in for record. 
Cloth tracings are, of course, stronger, and stand the handling much better than 
ordinary tracing paper, and do not become so creased as the latter ; an item that 
should be considered, because a mark of this nature on tracing paper and tracing 
cloth will generally become noticpable in reproducing by the blue-print or black-line 
process. 

ABBREVIATIONS. 
-Although we may dimension the lengths of reinforcement on the plan and 
elevation, it is very advisable to adopt some means of indicating exactly the length 
of each line by slopping it in some m.'mner, thus, on both i-in. and i-in. drawings 
the ends of each line indicating the reinforcement should be terminated by some 
mark. .\s the ends of bars and rods are manipulated in practice in various ways it 
is advisable on any drawings less than li-in. scale (upon which, of course, it is 
possible to draw the exact form the end of the bar takes) to use some sort of shorthand 
to indicate the various kinds of ends. The w-riter suggests that the following is an 
easily understood shorthand, which is clearly, easily, and quickly drawn, and it 
.avoids any necessity for putting wording upon the drawings to state how the ends 
are to be dealt with : — 



Turned-over ends thus 
Ordinary cut ends thus 
Fishtail ends thus : 
Hoolved ends tlius : 
("ranking thus : 
Wired junctions thus : 



AA>VW 



WRITING UPON DRAWINGS. 

Much unnecessary time is often spent in preparing drawings for reinforced concrete 
in writing particulars and descriptions of the work to be done, and the nature of the 
reinforcements. Not only would some standard list of abbreviations save time to 
draughtsmen, but the drawings would be clearer and interpretable by everyone 
consulting them. The following list of abbreviations is one that it is suggested may 
be employed with advantage : — 

Rods (round sections) ... ... ... ... r 

Bars (square and special sections'. .. ... ... b 

Wires ... ... ... ... ... ... ... w 

Stirrups ... ... ... ... ... ... s 

(Where two forms of stirrups are employed, one consist- 
ing of wire and one of flat or hooped steel, it may be 
advisable to use " w " for the former and " s "' for the 
latter.) 
Upper bars or rods ... ... ... ... u b or U r 

Cranked bars or rods ... ... ... c b or C r 

Distributing bars or rods ... ... ... d b or d r 

92 



fa; ^□Ny^B^ te-ndMAll 



STANDARDISATION OF DRAWINGS. 



Steel 

Reinforcing 

Sections 



Kounds 





S(|ii;iies 


. D 


Tec-s 


T 


Angles 


L 


Joists 


I 


Channels 


LJ 


Flats or Hoops .. 


F 


Special Bars 


Initial lett<- 


Sheet meshes .. 


In sections 



Pitch or Spacing 

lAs in columns or slabs) 

Feet ' 

Inches 

Square Inches ... in° 
Cubic Inches ... in' 
Imperial Wire 

(lauge I.W.G 
British Standard 

Section I5.S.S. 



letti'r or letters of trade name. 



On plans g+fffi 

In drawing these meshes on plans they 
should he shown on part only of each 
bay, the boundary line of the bay being 
fint'ly outlined, thus : — 
P 



Examples 



2 — l" ° Two 1-in. square bars. 

l" ^ i" p 1-in. round steel rods at 3-in. pitch. 

}"xl" "^s 1-in. flat stirrup. 

LETTERING. 
.-\s ret;;irds the lettering u|>on drawintjs, this should be large and open. Indeed, 
it cannot be too larjje. Of course tastes differ in regard to lettering, and in respect 
to drawings for architectural work of any artistic nature most persons would be averse 
to making any suggestions, but in respect to reinforced-concrete drawings, these are 
generally of an engineering character, and clearness is the sole object. The mistake 
usually made is in keeping the lettering far too small, no thought ever being paid to 
the drawing being reproduced at some future time. .This point is emphasized because 
there are so many drawings reproduced nowadays, and because one never knows at 
the conunencemcnt of .inv work what may or may not be reproduced later. There 
can be no objection to making tlie lettering as large as it is possible to get in the 
space. It does not look ugly by being large, and it always tends towards clearness 
to ever)'body concerned, while it will in many cases avoid the great expense which 
formerly it has been often found necessary to incur in the preparation of copies of 
drawings specially for reproduction. 

In .American engineering practice, some general standard style of lettering is 
apparent. Whatever lettering is adopted it should be neat and easily drawn, and the 
following alphabet is put forward as being likely to meet all requirements. The 
letters are drawn to minimum size, and can be increased WMth advantage wherever 
permissible. It does not really very much matter whether the lettering runs over other 



93 



REINFORCED COXCRETE. ICQINCiJI^ilJJ 

parts of the work, thouy:h u>;ually by a littU- manipulation and forrllioiit;ht il is 
possible to get this large lettering to work in quin- well. 
Alphabet for ordinary lettering ; — 

ABCDEFGHIJKLMN 
OP0R5TUVWXYZ 

uDcdefqhijk/mnopcjrsfuvwxyz 

Alphaliet in small ilalics for use in formula?:— 

bcdefghLj'klmno/jqrstauu/iy^ 

Note.- -Where capit.al letters are required in formula-, Roman letters are employed 
exactly similar to those shown in the .alphabet first recorded above. 

EXAMPLES. 

In connection with this article sonu- typical general drawings embodying the 
principles before mentioned, and to serve as examples of the manner in w^hich these 
can be employed in practice, have been prepared, and are shown in F,gs. i, 3, and 4. 

In the columns of this Journal drawings prepared by many of the well-known 
specialists have been reproduced from time to time, and it is not necessary to furnish 
examples in connection with this article, as this can be done by reference to former 

'^^"^\ilied with the subject of the standardisation of drawings is that of classification 
and tabulation of the designing, quantity taking, and estimating for same. This 
subject will be dealt with in a succeeding article. 



d. 



9+ 



[y, llDN.VIVDC-nONAlJ 
'Vli.MC.lNb:i!,KIN(i — J 



EARTHQUAKE PROOF ■ BUILDINGS. 



TT 







(f- 



-•fr 



REINFORCED CONCRETE f 



FOR EARTHQUAKE 
^ DISTRICTS. j£ 

% ty-j-"^' — TT"t— T."^1^""'^T.'"^'^^'' ipy^^ 
RECENT FRENCH AND ITALIAN VIEWS. 



The subtect of safe construction for ejrthqu.ike districts has tecome a matter of such 
importance that we are again devotinq space to this question, and present contributions that 
•we belie've are of public interest. We are indebted to our Paris contemporary, *'Le Beton 
Arme," for our illustrations. The line dravuings on paqe 97 TVfre kindly lent us ty the 
editor of " Le Ciment, ' ' Paris. 



Mich has been published of late regarding the utility of reinforced concrete for 
buildings in districts subject to earthquakes, and in a previous issue we published 
an article on this subject from the pen of Dr. von Emperger. From the many 
other contributions which are a])pearing, principally in the French. Italian and 
.\merican papers, we have selected a paper by Monsieur G. Flament Hennebique 
\\ liich we have summarised, and we are also giving extracts from certain Italian 
papers which were presented on the occasion of a competition organised by the 
Societa Co-o])erativa Lombarda after the Messina earthquake. 

There can be no doubt that monolithic structures of the reinforced concrete 
type, if suitably designed and well e.\ecuted, are the most preferable form of 
building construction at present available for earthquake districts. Buildings 
of considerable height can be erected with this material in districts sul)ject to 
severe shock. 

A FRENCH CONTRIBUTION TO THE SUBJECT. 

:\\ a recent meeting of the French .Society of Civil Engineers a pnper was read by 
.Munsieur l-Tanient Henneljique on the resist.-uii-c of rcinl..rri-.l r.Micrii.- l.iiikhntcs to 
earthquake shocks. 

The most interesting part of the 
coniniLinicilion is .1 re|Kirt on the 
lieliaviour of rcinforcrd concrete struc- 
tures, stated to have l)cen tlesigned on 
the Hennebique system. The instances 
recorded all refer to the great disaster 
in Southern Italy in December, icjoS. 

Although many of these struc- 
tures were in the are;i subjected to the 
most violrnt shocks there was no in- 
stance of failure. This is the more 
noteworthy as the buildings were not 
specially designed with a view to earth- 
quake resistance. 

The structures in question include 
the following : 

I. — Roadway over the Port.ilegni 
stream. This remained intact 
in spite of the debris which 
accumulated upon it (fi.i;. 9). 




REINFORCED CONCRETE. [CjINCBEJEJ 

2. — Floors of the Mandalari Hospital, which resisted and contributed largely to 

preventing the collapse of the house. It was not found necessary to remove 

the inmates. 
3. — Floors of the Cappellini Hospital, all of which resisted the shock. 
4, — Reservoir of 4,000 cub. m. capacity, which remained perfect, and continued 

to furnish water to the town. 
5. — The Messina Museum. The walls having collapsed, the reinforced concrete 

floors fell with them, but remained unbroken. One floor remained supported 

by three walls, the fourth having fallen. 
6. — VValls and beams of a basin at Gozzi. These fully resisted the shock. 
7. — Bridge over the Portalegni. This remained intact (Fig. 8). 
8. — House adjoining the church of the Madeleine. The reinforced concrete floors 

remained intact, the church collapsed. 
9. — The Natale mill. The building remained intact (Fig. 8). 
10. — Floor in the electric generating station of the railway. This floor had not 

suffered in spite of the enormous load it had to support on account of the 

collapse of the upper parts. The rest of the building, which was in the most 

severely shaken part of the town, was much cracked. 
II. — Wai ting-room at the Messina Railway Station. Remained perfectly intact, 

althoug'h the adjoining structure in ordinary masonry was much cracked. 
12. — Hospital attached to the Medical School. The building was completely 

destroyed with the exception of those parts which were in reinforced concrete. 

The staircase remained standing in the ruins (Fig. i). 
13. — Dwelling houses in reinforced concrete remained standing when all the 

surrounding" buildings collapsed. The proprietor and his family in one of these 

owed their lives to this circumstjince, all their neighbours having perished. 

M. G. Flament Henneoique's Views. — In designing rein forced-concrete 
structures for districts subjected to earthqu.ake shocks the aim should be to arrange 
the structure in such a way as to form a monolithic cage. 

The simple rectangular form is quite suflficient under such conditions. There is 
no need to limit the height of buildings if the base is broad and the upright and 
horizontal portions firmly united together. 

With ordinary buildings the tilting action of the shock causes each wall to pivot 
about its base, and a wall may be flung off in this way without disturbing the founda- 
tions (Fig. ^ I. This is impossible with a reinforced concrete building, which tilts as a 
whole. 

In the Messina earthquake there was very little disturbance of foundations, and 
M. Hennebique is of opinion that the imfxwtance of these is secondary, although rein- 
forced concrete piles, etc., may be necessary in erecting heavy buildings on shifting 
soil. 

Figs, ij and 14 illustrate the remarkable effect of a moving soil on large rein- 
forced concrete flour-mills in Tunis, the buildings having tilted as a whole without 
anv cracking taking place. Such an accident, although altogether exceptional, indi- 
cates the probable behaviour of a reinforced concrete building on loose ground in the 
event of an earthquake shock. 

SOME ITALIAN CONTRIBUTIONS TO THE SUBJECT. 

We have referred to the essays which were presented in connection with 
the Italian competition instituted after the Messina earthquake, the first prize 
having been obtained bv M. Giulio Revere, of Milan, editor of 11 Cemento, in 
collaboration with M. Mttorio Gianfranceschi. The following is a summary 
of the essay which gained this prize, and which was entitled, " For Calabria and 
Sicily " : — 

Essay by M. G. Revere and M. \'. Gianfranceschi. — The authors prefer a 

96 



" EARTHQUAKE-I'ROOF " HUILDISGS. 




rigid slructiiif, resting freely on llie soil, to one which is rigidly connectisj with the 
soil bv means of heavy foundations. The main foundatioii may consist of a single 
plate, only slightly project- 
ing beyond the walls, and 
this system the authors 
consider the best when the 
site is on loose soil, or it 
may be made up of broad 
soles beneath each of the 
walls, cross-connected at 
intervals. When a h.ird 
foundation is only dis- 
covered at some depth 
below the surface, a plate 
may be constructe<l ;il a 
low level, a frame .at the 
higher level being con- 
nected with it, forming a 
base. Neighbouring 
houses should be isolated 
from one another, .ind 
cellars should be avoided as 
far as possible. If the pre- 
vailing direction of the 
shocks be known, the 
orientation of buildings 
should be, as far as 
practicable, such that the 
waves impinge diagonally, 
,ind not normally, on the 
walls. The plan, proposed 
by some engineers, of 
avoiding any rigid connec- 
tion of the uprights with the base, is to be condemned. 

The necessity of a thoroughly fireproof construction is insisted on, in view of the 
fact that earthquakes are so frequently followwl by extensive confiagrations, and both 
masonry and steel frame con- 
struction are rejected as means of 
solving the problem. The latter 
system, so widely adopted, is con- 
sidered unsuitable for Sicily .and 
Calabria, the districts chiefly con- 
sidered in the competition. The 
difficulty of finding skilled smiths 
is there very great, and this, 
.added to the liability of steel struc- 
tures to corrosion, and the fact 
that the most severe stresses are 
localised in the joints, are serious 
objections to the adoption of steel. 

The system of construction 
in reinforced concrete fulfils all 
the conditions of stability under 
shock, and of resistance to fire. {iz-^rALr,^--^!!-^^.-. ■^■r^^^^.-^^^^-r^^^-^-.^-i-^^^^.,^^^^^-.. 

It has, however, been objected F:r,. 3. Showing .\rranoement of the Principal Rous 

that a high standard of work- »■■ * Building, 

manship is indispensable; that 

a large quantity of wood is necessary for centering and shuttering; and that the system 

does not lend itself readily to the construction of the double walls, favoured in 





97 



REINFORCED CONCRETE. 



iCDNCBETEl 






I<'^-£Noi'Ni^"'i?iN'^~J " EARTHQUAKE I'ROOF' BUILDINGS. 

those districts as a means of resisting' the hot climale. 'I'lie authors propose to 
«nercome these dilliculties by constructinj^ biiildinj^s in hollow concrete blocks with 
reinforcement. 

Hollow blocks, provided with loni^ilLKJinal jj^rooves for the reception of the rein- 
fcirceinent, arc readih' manufactured by an ordinary block machine. Uound rods are 
U'^ed, all joints bein^ made by crooking the ends .and binding with wire. The form 
<if the blocks .and the arr.-mgement of the reinforcing rods are seen in i'lj,'. 2. The 
arr.ingemcnl of the principal rods in ;i building is seen in /'/'.i,'. 3. .\rchcs and vaults 
are to be .•ivt)ided, being replaced by horizont.al be.ams or lintels. 

l"" 1,00ns.- If the construction of reinforced-concrcte floors 111 situ is impracticable, 
concrete beams, reinforced symmetrically, .are to be preferred. Failing them, steel 
or wood joists, united at intervals by reinforcing rcxls placed transversely, may be 
used. The llooring niateri.al should be light, .and ceilings should be dis|)ensed with 
as far as possil)lc, h'l.it roofs, as generally .adopted in Southern llalv. are to be 
recommended. 

.SiAiucAsKs.— .Stairs should be solidly built in, either between two walls or 
su|)ported on the inner side by an inclini-<l reinforced-concrete beam, the use of light 
■decking for the stairs being avoided. 

The method proposed lends itself to decorative treatment, either by moulding or 
colouring the external faces of the concrete blocks or by inserting panels of natural 
stone, care being taken to anchor (he latter firmly to the structure. Iioth dwelling- 
binises and large buildings m.ay be constructed in this w;iy, with such labour .as is 
usually av.-iilable in the regions subject to earthquakes. 

From the other essays presented on the occasion of the competition we 
ha\e sckcted those of Professor Donghi, M. Antonio del Pra and Messrs. E. 
V'ianiiii lS: Cn.. as being ie]iresentative of Itahan ideas on the subject. 

Professor Donghi's Views. — The first pam|)hlet before us is that of the celebr.ited 
architect. Professor li.iniele Donghi, chief engineer of the Venice municipality. It 
was published by the Committee V'eneto-Trenlino, and applies to Calabria .md Sicily. 
The author calls .attention to the fact that there is still little known as to the causes 
<;f seismic movements. Nevertheless, he foresees that research in this field will at 
least help to define geographically the zones more or less ex|Misecl to earthquakes, and 
thus enable us to ])rep.ire for disaster. To prove this he reproduces what ni.av be 
termed an earthquake map of Italy. 

There are four questions to determine. First, to indicate the location of a seismic 
zone in which the elTects of the moving earth are not extreme; second, to compel the 
adoption of systems of construction best calculated to resist such inovements, i.e., the 
adoption of indestructible buildings; third, to prepare to give prompt assistance when a 
disaster happens in the seismic territory; and fourth, to at least convert, if possible, 
unsafe buildings into safe structures. 

.After pointing out the necessity for an organisation designed to give prompt aid 
to victims, such as .i disciplined body of men prepared to engage in rescue work at 
short notice, to protect [XTsonal property, and distribute food, medicine, clothing, and 
disinfectants, all working under suiiervising authority at Rome, the author comes 
to the subject of construction, presenting, in part, the follow'ing conclusions : — 

The choice of the land should be m.ade based on the following prescriptions 

already known : avoid the ground having a thin layer of soft material with hard 

rocky underground, hilly land having an inclined rock formation, isolated hills, the 

points of discontinuity in land formations, the zone too near seashore, those too 

rich in minerals or hot springs. 

To resist earthquakes buildings should have a monolithic, elastic, and 

indeformable construction, .-\void constructions of only lumber and those in which 

lumber is given the function of resistance. Reinforced concrete structures are 

the safest. 

99 



REINFORCED CONCRETE. 



[CQNCREJEJ 





LEM<.INt.t.WIN>i ^J 



HARTIIOUAKEPROOF " BUILDINGS. 



The first problem th;it we must meet is the determination of the external 
forces th.it the building will have to resist from the shocks. The exposure of the 
house, if possible, should be such th.it the dircclion of the strongest shocks will be 
transmitted diag-onally to the building^. 




The houses may be separate or attaclied to each other as well as in straight 
lines; in the latter case the first and the last buildings should be reinforced with 
piers to resist the shocks at the extreme points. 

The height of the houses should be in proportion to their base. 

The foundation should be monolithic and level and should cover the entire 



REINFORCED CONCRETE. 



I CQNCBETEI 



ground space of the buildinij; the foundation floor sfiould not be curved, because 
the length of the seismic waves is very great and the radius of its curves is small. 

The walls, according to the author, should be well tied to the foundation and at 
the same time expansion joints in the side walls should be provided for internal 
tension and to avoid the sharp vibrations. 

The corners of the house near the bottom should also be tied \\ ith curved piers 
to break the stocks, which would be separated and run along the outside platform. 

In consideration of its strength and durability the material to be used is rein- 
forced concrete. 

The author believes that a skeleton of well-ma3e reinforced concrete would be 
efficient, and suggests that the ruins of Messina and Reggio be used in the 
concrete that will be needed. 




M. Antonio del Pra's \'iews. — \ery similar to the Donghi idea is that of the 
engineer .\ntonio del Pra. He, too, gives reinforced concrete the preference, but 
suggests a method of construction with concrete blocks or bricks likely to resist shock 
if it is necessary to use these materials for economical reasons. He would have blocks 
or bricks tied at the joints with hooks inserted in the foundation floor, also chained 
with reinforced-concrete beams inserted in the walls in such a manner as to form 
spans to the windows and continued for the whole length of the walls. Ceilings should 
always have two sets of beams, one to support the ordinary loads, the other to do 
the work only in case of shocks, and reinforced by hooks and diagonals, which will 
make the ceiling more like a large horizontal reinforced beam. 

Thus the walls are made to oscillate together. The resulting construction should 
be monolithic. Every care should be taken in laying bricks and also in the preparation 
of the mortar, which should always be enriched with at least a third part cement. 

As to reinforced concrete houses, the author is perfectly in accord with Professor 
Donghi. Given a choice, he would have the ceiling reduced to a skeleton of reinforced 
concrete with lighter construction, such as timber, for internal ceilings and artificial 
stone tiling for the roof. 

Messrs. E. Vianini's Views. — On a different basis is the plan suggested by the 



Uv-FSof™^"!'!^^ " I^ARTHOUAKR-PROOF" liUlLDISGS. 

Six. i;. \ i.cniiii i\ Cii., of Rome. Thi^ is also a rfinforcctl-concrelf ty|je, bul 
iiilr(«hicinj.f novel features by i>rovidiii)^ for a superstructure whose members will be 
iiukpeiulent of the concrete floor. To meet and resist undulatory shocks the desifjners 
would have the house free to move on its foundation, so to s|X'ak. This Ihev believe 
could be accomplished by buildinf.; on a smooth rein forced-concrete foundation, 
considered not only as a sustaininj^ floor, but also as ,i slidinj^' floor when the violence 
of the shocU surpasses the resistance of the buildinf^. Thus the house would be com- 
posed of a combination of structural parts of special dimensions laid over each other, 
hut free lo move independentlv. 




Tunis Tiltkh 



103 



TESTS. 



lOONCBETEJ 




^^^^^^^^U^jg 



=H» 



TESTS ON REINFORCED 
i^U CONCRETE CONDUCTED 
IN GREAT BRITAIN. 

(PART V.) 



T.'ie atsirnce of systematic testing relating to reinforceil concrete h^s placed this country 
at a disadvantage in the utilisation of this modern material for structural purposes. Ex- 
cepting only in regard to fire tests, such in'vestigations as have teen conducted have been 
quite spasmodic in character, and practically altvays of a purely private nature. 

Having regard to the fact that the question of a series of tests being conducted in this 
country, in a systematic manner, is having the attention of the Institution of Civil Engineers, 
the Concrete Institute, and other scientific societies, •we are presenting particulars, as far as 
tve are able, in chronological order, of such tests as have been conducted in this country 
from time to time, and this may serve as a useful guide to those 'who have the arrangements 
of the tests of the future. 

The first four articles of this series appeared in our May,September, Novemberand January 
numbers respectively. The follo'wing particulars of tests are new presented, and further 
articles 'will appear from time to time. — ED. 



INDENTED STEEL BAR TESTS. 

Fig, 25 shows the detailed construction of a flour at the Waldorf Hotel, London, reinforced with 
" indented steel bars," one panel of which was tested in January, 1907. The floor was that of a private 
dining-room on the main floor, and was designed to carry a safe load of 2 cwt. per sq. ft. The panel 
was supported on main girders 10 ft. lo^ in. centre to centre, the length of the panel being 26 ft. 11 in. 
The concrete slab was 5i in. thick, the concrete being made i part Portland cement, 3 parts broken 
brick, 2 parts sand, and 2 parts coke breeze, the aggregate being crushed to a sice of about i in. The 
concrete was all mixed in a Smith mixer. The reinforcement consisted of i in. indented bars placed 



ju- 



,>»,» ' >,l^.,.,i,,}i„^i.,>,/ .m:!m,,!,ii,7777r7!! 



2.: Ti.-——^^' ■ -^s-'^^^w- . 


• • ^ 






- . - - .,-_.-;.---_. _ — J— r:-» i^ 


H.I42 




.- ■^- 


^tri'. -*ir ^oA^r r»^,r T ' «'- 


^i.1. i-CG 'TuO^/^tTL. Af^s ^Ke. 




'_» 




(5~./,e7-c ^^o^<K u~o^^j,o^ j,^^ 




















£xTcrfO aryo^o 'y ^T arMCM 


;' -:. 






/„ £^0 T^^CS Ti. B,^z TO 


o« 












Fig. 25. Co 



Waldorf Hot 



5i in. apart centre to centre, with four cross bars in the panel at a spacing of about 2 ft. apart. The 
test load was applied by means of bags of cement placed in layers on the floor, the final load being 
4 cwt. per sq. ft., or twice the calculated safe load. The deflections were as follows : — 



Load. 
Cwts. per sq. ft. 



Deflection of 

Concrete Slab. 

Inches. 

A 
i 



Deflection of 

.Main Steel Girders. 

Inches. 



On the load being removed, the permanent set due to deflection of both girders and concrete 
proved to be J in. No cracks on the underside were noticed. The test was conducted by the architects, 
Messrs. Archibald Mackenzie & Son. 

104 



TESTS. 



H.I43 



.^^y.,^^/^f:Z^r^c'^ ^iS^ ^^^^^r^ 



Fro. 26. Construction of Test Floor at 1,ivki»i'ooi . 1908. 



Fig. 26 shows another test, in April, iqofi, of a floor at Liverpool reinforced with indented bars 
A wet ganging of concrete was used in the following proportions : 3 parts clinker, 2 parts gravel, i part 
crushed brick, and i part Portland cement. The test slab was made February 28th, and tested on 
April 4th. The thickness of the slab was .( J in The following were the deflections recorded at various 
stages of the loading ; — 



Time. 


Apr. 14, 
1908 


Apr. 14, 
igoS 


Apr. 14, 
1908 


Apr. 14, 
1908 


After 48 Apr. 22 
hours 1908 


Apr. 22, 
1908 


Apr. 22, 
1908 


Apr. 22, 
1908 


Apr. 22, 
1908 


load, total 


~ 


162 cwt. 
4 lb. 


102 cwt. 

2 lb. 


133 cwt. 
3 lb. 


~ 


Release 


None 


~ 


Sand 
15' 
de«p 


Sand 
2-6- 
deep 


Lo-id ptT sq. ft. 


i cwt. 


861b. 


14a lb. 


207 lb. 


- 


- 


- 


i cwt. 


- 


- 


Deflection nt E, inches 


='. 


'' 


n 1 «^ 


n 


ii a 


a 


n 


1 n 







H 



HENNEBiqUE TESTS. 

.\ portion of the floor of the new Sorting Olhce at the General Post Olhce, Si. .Marliii » li-drand, 
London, constructed of reinforced concrete on the Hennebique system, was tested on September 23rd, 
1008 The portion tested 

was a complete bay with I 1 \7777 ~ .rj- ■■ 

the superficial area of 40 ft. 
by 35 ft., or 1,400 sq. ft., as 
shown by Fig. 27. The bay 
consisted of six secondary 
beams 8 in. wide by 18 in. 
deep, excluding the floor 
slab, which is 3* in. thick. 
The beams are spaced 5 ft. 
10 in. apart at centres, and 
have a span of 40 ft. be- 
tween the centres of the 
supporting beams and 
columns. The secondary 
beams are reinforced by 
four I J in. dia. tension 
bars, two J-in. dia. com- 
pression bars, and numerous 
stirrups for resisting diag- 
onal tension or shearing 
stresses. The floor slab is 
reinforced by J-in. dia. ten- 
sion bars running in two 
directions at right angles to 
one another, as well as bv 
stirrups hke those in the 
beams. The arrangement of 
the bars in both elements of 
the construction is that 
always adopted in the 




9CA.l_c or FtCT 
1. 2.3.-4.5. 6.SH0W POSmCTHS of DtFLtCnON MCASURIMO IhSTRUntNTS 



LOADS 


■ READir.4G o(s iMsrmunEr-rrs ■ 


Remarks 


(>) 


(2) 


C3) 


(4) 


(5) 


(6) 


LQA.DINCJ Nil 


















£3 . . 06 


D9 ICwT 


■y^. 


'^ 


^u. 


76^ 





'^ 


DS liCWT 


^%^ 


]°M 


'%^ 


?^ 





-4^ 


/NLOAQNalOvT 


'%^ 


'^ 


Y^ 


X* 





f/M 


=tAONcrtT»<tN-9-30Pn23 900 


DC ICWT 


''M 


^ 


!i^-4 


^ 





%^ 


=lEAC!<MOS-T>.Ktn 6-30AM 2-4 COS 


□ a Nic_ 


>&4 












=lE«3.rW>T*«EM10Af~1 23 (? OO 



















105 



TESTS. [0:?^CBETE] 

Hennebique svstem, and now so generally familiar. The concrete was made in the proportions of 6 cwt. 
Portland cement, 13J cii. ft clean sharp sand, and 27 cu. ft. washed gravel crushed to pass through 
a J-in dia. gauge. The floor was designed for a working super load of i cwt. per sq. ft. 

The first test consisted in spreading the load of 70 tons or i cwt. per sq. ft., over the area selected, 
deflection being measured at the centre of the three supporting beams by delicate instruments gradu- 
ated in 64ths of an inch. Loading was started at g a.m. on September 23rd, after the instruments 
had been adjusted in position below the centre of the beams, and other instruments at the ends to 
measure the downward move.nent of the supports. Under the normal load o! i cwt. per sq. ft the 
following results were obtained : — 





Beam 

No. 
1 

3 


Defleclion 

Total At Support Nett 

JJ ^i H 

y a'i li 


Proportion 
of Span 
1-21+0 
1-2300 
1-2730 


Under the full test 


load of I.J c 


wt. per sq. ft. the results were : — 




Beam 
No. 
1 
2 
3 


Deflection 

Total At Support Nett 

S3 s"[ ijS 

s? - K 

SS A ii 


Proportion 
of Span 
1-1500 
1-1500 
1-1670 



The estra loading was removed by 9 p.m., when all the beams immediately rose to the extent ot 
about S5 in. at the centre of the span, readings taken at 6.30 a.m. and a-tn- on September 24th 
showing that no perceptible alteration had taken place in the form of the beams during the 12 hours 
following the removal of the extra loading. 

At II a.m. on September 2.jth removal of the normal load was started. By 5 p.m., when one- 
third of the load had been taken away, the average rise of the-beams was rather more than fy. 

On September 25th at S.30 a.m., when half the norma! load had been removed, the beams rose to 
the extent of /j in. at the centre, and at 10.45 a.m., when the floor was quite cleared, the instruments 
showed that the construction had quite regained its original form. 

KLEINE TESTS. 

Below we give particulars of tests on " Kleine *' patent reinforced hollow-brick and con<rete 
floors, full details of which are given in the illustrations and the description. 

Careful precautions were taken to ensure the load being truly distributed on the slabs. In par- 
ticular, we may instance the London test in which, we believe, the arrangement of applying the load 
was similar to that at Charlottenburg. 

We also call attention to the fact that all the tests were made on freely supported slabs. Of 
course, when floors are built into iron girders by the " Kleine " patent fire-resisting flooring, the design 
of the floor is altered shghtly so that the resistance in section of the floor would be different for the 
same spans, as in the particulsir cases of the tests noted. 

In the test carried out at Messrs. Higgins' brickfields at Cheetham, Manchester, the floor was, 
constructed as follows ; Hollow bricks, lo in. by 6 in. by 4 in., with a central web, and an average 
thickness of material of i in. were laid on centering in eleven longitudinal rows, alternately on edge 
and on flat, and breaking joint. The vertical joint between courses averaged | in. thick. Embedded 
in each f'g in. above the soffit was a strip of hoop iron 2 in. by 0-17 in. running the full length of the 
joint. .-Ibove the bricks, and bonded to them by the alternate brick courses on edge, was a layer of 
concrete alternately 55 in. and 71 in. in depth, bringing the total depth of the floor up to ii| in. 

The vertical joints between bricks were made of cement mortar composed of i cement to 3 of sand. 
The bonding referred to above, produced by laying the bricks alternately on edge and on flat, was for 
the purpose of preventing thrust and shearing. 

The floor had no side support, and rested freely at each end on a 5 in. by 2^ in. iron rail, with a 
clear span of 12 ft. The weight was borne by the rounded upper surface of rail 2^ in. wide. Each 
rail was bedded in cement on a 13} in. brick wall, 2 ft. 9 in. high. The width of the floor was 5 ft. 3 in. 

.\t each side of the centre slab was a strip of flooring r6 in. wide, continuous to, but quite inde- 
pendent of. the centre slab ; the intention being to show that the centre slab would deflect without 
in any way affecting the side strips, which proved to be the case. 

The floor was designed to carry a safe working load of 2 cwt per sq. ft., with a factor of safety 
of 1 ; gi\'ing a breaking load of 8 cwt. per sq. ft. (The actual breaking load exceeded this amount, 
as shown.) 

In loading for the test a space 6 in. wide was left uncovered at each end of the'span. The 
remaining space of 11 ft. by 5 ft. 3 in. or 57J sq. ft. was covered with an evenly distributed load of 
common bricks, 12 of which weighed 113 lb. The weights per sq. ft. refer to this area of 57I sq. ft. 

106 



r 1. 1 C<N.vrBIK-l lONAl.l 
!'>■ t.N(ilNt:KHlN(i — J 



TESTS. 




To avoid any reduction of pressure througli the brioks (orminR an arch across Ihc span, thcv were 
piled up in six i8-in, wails, and one i2-in. wall across the floor, with a clear space between walls of 
I in. In the twelfth course and upwards, this space was incre.ised to 3 in. by reducini; the thickness 
of walls. 

The illustration {Fig. 
28) shows how the meas- 
urements were taken. 
Under the floor, at the 
centre of its length, were 
three upright posts, to 
which were fixed carefully 
drawn scales. Stout hoop 
irons fixed to the soffit of 
floor pressed lightly against 
these scales, and enabled 
the deflection to be read 
to 100th of an inch. 

.\t each end of th" 
floor a stout post fixed into 
the ground and a rod 
projecting from the lower 
part of the floor enabled 
similar readings to be taken 
of any slight outward 
thrust due to the deflec- 
tion. 

\ test was conducted 
by .Mr. R. D. Sandiland- 
architect, at the works . 
Messrs. Bladen & ("> 
Parkhead, Glasgow, .: 
December 6th, 1907, on 1 
floor constructed on t!i' 
Kleine system. This w.i~ 
composed of hollow brick- 
10 in. by 6$ in. by 4J Id 
the thickness of the mat' 
rial including the cenir 1 
web was i in , the brie I. 
were l.iid on centering n 
longitudinal rows, tli 
joints between each n 
being S in. wide, with .11 
iron strip ij in. by 011 
in. gouig from end to cr 
of longitudinal joini 
The bricks were laid alt i 
nately on edge and on flat, 
and the whole surface 
co\ered over with concrete 
to a depth of 3} in. over 
bricks on edge, and 5} in 
over bricks on flat, the 
total thickness of floor 
being 10 in. The com- 
position of cement mortar 
was in the proportion of 1 
to 3, and the concrete i to 5. 

The floor was supported at each end on beams 5 in. by 4! in. filled with cement, and resting 
on 14-in. brick walls built in cement, and about 3 ft. high : the distance between the beams gave a 
span of 12 ft. 

The width of the floor was 5 ft. 4 in., and at each side there was a strip of flooring i ft. 5 in. wide, 




TESTS. 



ICDNCBETE) 



but disconnected from the main portion of the floor by n strip of felt the full depth of the floor, and 
as the load was put on and the fioor deflected, the sides remained as at first, and were in no way 
a'Tected by the movement. 

The floor was constructed to carrv a safe load of i J cwt. per sq. ft., with a factor of safety of 4, 
thus givins a breaking load of 6 cwt. per sq. ft. This was exceeded. 

The floor was loaded with bricks up to within 3 in. of rest at ends, and to within 5 in. of joint 
at sides. The bricks were built in seven walls across the floor with a clear space of about 3 in. between 
each wall to prevent the bricks from coming to.gether at top and thus forming an arch across the span. 

The area loaded — 4 ft. 7 in. by 11 ft. 6 in. = s:'3 sq. ft. — was covered with a distributed load of 
bricks, roof which weii^hed 84 lbs. The illustration will show how the bricks were placed on the floor, 
and also the position of the scales by which the deflection was arrived at. 

The deflection was not noticeable until a load of nearly 2 cwt. per sq. ft. had been built up, after 
which the deflection was gradual until a load of 5 J cwt. per sq. ft. had been reached, when it was seen 
that the floor was lea\ing the strips of flooring at sides. The loading was continued until a weight of 
6'38 cwt. per sq. ft. was reached, when it was found that the deflection was equal to 0-4. The floor 
was then left standing, and on examination 14 days later it was found that the deflection had only 
increased to o'6. It was still standing under load on May "tli. 1008. 

BLACKADDER'S TESTS. 1906. 

Some tests were conducted in 1904 by Mr. William Blackadder, B.Sc, C.E., of dlasgow, when he 
was in the Harbour Engineer's Office at Aberdeen. In these tests the usual method of loading the 
beams directly with bars of cast iron was not employed, -Mr. Blackadder feeling that this was not an 
accurate enough method owing to the interlocking of the cast-iron bars used. He had not a testing 
machine available of the ordinary character so he constructed one made entirely out of old timber 
used in temporary works round the harbour, and the loading was done with cast-iron bars from the 
same source. It was really a compact lever, its action being similar to the ordinary " nutcracker." 
It consisted of a lever of two pitch-pine piles 12 in. bv 12 in. and 22 ft. long, bolted together just as 
taken out of a cofferdam, held at one end bv a chain to the lower beams, and loaded at the long 
end by the cast-iron bars. By prolonging the beams to beyond the end of the lever there could be 
no overturning of the machine about either end. .^ represents a beam to be tested (Fig. 30), and the 
way in which the load is transferred to the beam at points (aa) through the transfer beam T is clearly 
shown. Considerable accuracy was obtained with this machine. The lever was weighed and balanced 
to find the exact centre of gravity. The chain had shackles on each side to admit of adjustment so as 
to keep the lever " floating " level. Under the lever was put a rocker made of jarrah wood to allow 
free motion of the lever and prevent load being transferred to one end of the test beam if lever were 
out of the horizontal ; and a similar rocker was put under the first to keep the load central on the 
transfer beam in case of any tendency of the lever to rock sideways. The transfer beam loaded the 
test beam at two points (aa) equidistant from the centre of the span. On these load points on the 
test beam were put rockers (K4 on drawing) of J-in steel plates and 2-in. round bar freely allowing 
for deflection of test beam. Similar rockers (Ri) were placed at the supported ends of the test beams 
to allow the ends to cant freely when deflection took place. Measurements of the lever arm of machine 
and position of cast-iron bars, which were previously weighed, were taken, and so knowing the span 
and position of the load points (aa) the actual bending moment applied was very closely obtainable. 
The test beams were S in. by 8 in. by 7 ft. 6 in. (6 ft. 8 in. span), composed of concrete i cement 
2 sand, 3i of i-in. to J-in. granite reinforced from '52 to i'43 per cent, (some with inclined shear mem- 
bers, consisting of 3 in. rods slipped over the lower rods as shown in Fig. 31). Expanded metal and 
concrete slabs were also broken with the machine. These had expanded metal No. 8 in the lower side 
and were 3 in. thick. These were loaded centrally. 

The following table gives the particulars of the experiments conducted on slabs reinforced with 
expanded metal : — 

T.\P.LF, I. 





\-alueof »i=M 


Experiment 


.Avera-re of 
Experiment 


■46 per cent. 


-'-,2. 303. 303 (37'.) 

110. 3*12. 3S0 

3:7. 3.1 '■ 3 3-1. 3i" (40^ 








TESTS. 




The results in partiitlieses have been neglected in (•;ll(•ulatin^ the averaaes, as Mr. Blaikadder 
thought such high values open to suspicion, the load perhaps not being frcelv distributed over the slab. 
The results of the tests on the beams arc shown in Table II. 



TABLE II. 



Diam.of Percentage of ^ Bre.ikiny 
Rods. Reinforcement. Load(Tons) 



3-45 
3-25 

3-95 
4-40 
4-77 

5 '.50 
5 'JO 



No shear reinTorcemeDt. 
Do. 



Do. 

Do. 

Shear reinforcement. 

No shear reinforcorfienl. 

.Shear reinforcement. 



In his investigations, .Mr. Blaokadder adopted th» value of 2,140 lbs. per sq. in. as the compressive 
strength of the concrete, and 170 lbs. per sq. in. as the tensile strength 



FT 






.^- 






Fio. 31. Beam with Incliseh .Sheari Rkink.rikmekt tested uv Mk. Wn tt.m lii, 

I r 1 



! I I 



w k d 



SECTION OE BEA.M SHOWING ARRANGEMENT Ol ShEAR MeMUERS. 

TESTS FOR MR. A. E. WILLIAMS. 

Some tests on reinforced concrete beam, were coiulucied In October and December, iqo2, by 
Messrs. David Kirkaldy & Son for Mr. .-K. E. Williams, of Dagenham Dock, Esse.x. The form of 
these beams is shown in Figs. 32 and .33. 

These beams had relation to Mr. Williams's patented system of reinforced concrete constructi.ia 
which is worked by Messrs. Samuel Williams & Sons, Ltd. 



109 



TESTS. 




•>^ 



Fir,. 32. Beam of TviE KK 4261 te^-ti d i "R Mr. .\. E. Wii 




Another Beam of Type KK 4j(i 



Beam of Type KK 4264. 



I 



Beam of Type KK 3140. 3141, 3143. 
Fir,. 33. Beams tested f..k Mr. A. E. Wi 



The tables on page iii are copies of those included in Messrs. Kirkaldy & Son's report. 
The load in each case was centrally applied over a bearing of 13 in. long. 

We also give in connection with same the results of tests on cubes of concrete so as to provide 
data of its strength. 











1 


r.ick.'.l Sli;;htlv 


Cm- 


1.^1 




Test 
No. 


Description 


Dimensions 


.■\rca 


































Stress 


Per s.i 


Pe.- sq. ft. 


Stress 


Per sq. 


Pers-. 


ft. 






in. 


sq.in. 


lb. 


lb. 


tons 


lb. 


lb. 


tons 




KK 


Made from same mixing 
of Concrete as KK 




















3143 


Marked i. Beam 3140 


6-00 6-00 X 6-00 


36-00 


70,800 


1.1'.; 


126-5 1 

ii6-) 


70.800 


1.967 


.26-,, 


2S-2 


3144 


Marked 2. Beam 314 1 
KK 


6-00 6-OOX6-00 


36-00 


59.400 


:.65o 


u.6-1 1 


72.810 


2,022 


130-0 \ 




3145 


Not marked. Beam 314:: 


6*05 6-04 X 6-00 


36-24 


48.000 


1,340 


sfi-s 


St. 720 


2,25.^ 


14Vn 





I J. I ON.VI BUCTIONAU 
l'\ t.NdlNfcF.BINl. — J 



rnsTs. 



























'I\ 






"1 


















« 






Ulfi 


u£ 




1 




Us 




III 
































•^ 










































ei 


£ Q 


__","' 




.< 




























" 


— 


£ 


i' 












1 


1 


1 






T'. 












^' 






f,-^ 








« 






:• r 
























;:t 





1 

























































































'^ 












% 


1 




-. 


; 


s 




j3 


^ 




r 


~ 












































































C/1 


>c 










;- 


























































.2 


U-, 












c 


g 








^_^ 
































^- 














s 




^ 


„ 


^ 
































o 


-'■ 








































^ 


l- 




^ 


■5 


^ 




^i 


■^ 












^ 


g 






p, 


^ 




















^ 




? 


? 


^' 




r 




. 


,^ 


- 




















- 








- 




5 




^ 
























n 




? 


? 


--■ 






















5t 


cl 


ft 
















G. 


= 


2 


2 


2 




C '/I 


a 




- 


- 




E.S 


.3 


X 


X 


x 




Q'" 


X 


^t 


- 


- 








•^ 


'^ 


^ 






t'i^ 


^- 


.=" 


j.- 








to 


^ 


o 
















1 




^ . 


i S c 


_^ c-c 


















■s -S > 


■s.< 




- 






Jlilj 


te 








|:,:-;:- 


■\' ,■"■-'- 


^'' -■•.'.• 'J 'i"^ 
























^Z 




5 


r. 


:x 









1 ? 




.c 

c 


1 1 II 


,> f . % 


\ 1 ^;t ;:s 


% 


;; & 


I 


g s- 


% : 


1 


r ? 


1 


f f^ 


g 


1 P 


1 


f • 1" 


1 


§■ ^ 


^• 


? ? 


;- ' § 1 1 S 


E. 


^ 


P 


"" K K 


1 


Concrete composed of 
2 parts J shingle, 
I part sand, \ ami 
three bags _of cement 
to the yard 

Marked Nov. 3, 1902. 
Four rolled steel joists, 
3" X I ft", and two brac- 
ing joists, as sketched 

Marked Nov. 3, 1902. 
Four'rolled steel joists, 
3" X iV y and two brac- 
ing joists (as sketched^, 
all lapped with iwire 
20" dia. wound spirally 
about 3' pitch 


h2 


2 If 



TESTS. 



ICQNCBETEJ 




LEWIS CONSTRUCTION 
CO.'S TESTS. 

Vtcst on a two inuut.'ii' old 
beam'was made by the lewis Con- 
struction Company on January 7th, 
1909. This beam was T shape, 
consisting of No. 2 section dovetail 
corrugated sheeting (27 gauge) and 
No. 8 il-in. wrought iron round rods 
placed as shown in the diagram 
(Fig. 15). The concrete was gauged 
I part cement to 2 parts sand and 
4 parts of ballast, crushed to pass 
a J-in. me^h sieve. The span was 
9 ft. in. in the clear. 

The result was as follows : — 



:;^ 






11— f^ 



Load 


Deflection 


.Applied 


(.Approximately) 


2 tons 


Nil 



9 ., 4-1 lb. ... broke 

It was found on inspecti(m that 
the rods had not been broken, but 
only bent, and that the fracture had 
taken place exactly in the middle. 

On .August 7th and 8th, 1908, 
the same firm tested a reinforced 
concrete slab floor, .sj in. thick and 
II ft. 6 in. clear span. The slab 
was constructed on July 7th, so 
that it was one month old at the 
time of testing. The same was 
placed on two supports with over- 
hanging portions, the intention being 
to make the slab act as a continuous 
beam, but it was noted that the 
cantilever portion slightly lifted 
owing to insufficiency of weight for 
the anchorages of these parts, and 
the deflection was therefore in- 
creased. However, the loading and 
deflections were as follows : — 



Load -Applied 


Deflection 


2 tons ... 


Nil 


4 „ 
6 „ 
8 


} in. 
i „ 


10 ,, 

12 

14 „ 


... i-A ,. 
- If „ 
... 2i ,. 



8 cwt. 2 qrs. 2-/a 



r y. CiONMUllC-l lONAlJ 
I'V tJM(ilNt:tJ>INtt — J 



THSTS. 



At (lie liiiK' Uic loading was discontimipd it will be scon that the total load was if tons 8 cwt. 
zqrs. iS lb., which is equal to 8-4 cwt. per sq. ft. This load has boon left on the slab until the present 
date, and no further deflection has been noted. Tli"! slab is 3 ft. wide, and it was constructed with 
I J in. by x] in. by J in. H bars, placed 2 ft. apart at the centre, and a sheet of dovetail corrugated 
metal inserted between, and, in addition, six {\ in. by i in. bars were placed over the supports and 
cranked downwards as shown in lig. j.( for the purpose of giving continuity and reinforcing 
the cantilevers. Three of the rods ran the full length of the slab, being continuous, and therefore 
in addition to the sectional area of the H bars we must add these three ;'„ in. by 5 in. bars. The 
concrete was gauged i part cenunt to 2 parts sand and .( parts J-in. ballast. 



9- -5'^ 
lO- Oi 




THE CONCRETE INSTITUTE. 



[Ca^CBETE] 




RECENT VIEWS ON 
CONCRETE AND REIN- 
FORCED CONCRETE. 



THE CONCRETE INSTITUTE. 



// is our intention to publish the F.ipers jnj Discussions presented before Tedinical 
Societies on matters relating to Concrete and Peinforced Concrete in a concise form, and 
in such a manner as to be easily available for reference purposes. 

Ttie method ive are adopting^ of di'viding the subjects into sections, is, ive believe, a 
neiv departure. — ED. 



A General Meeting of the Concrete Institute was held at the Royal United 
Service Institution, W'hitrhall, S.\\'., on January 20th. and the attendance 
was considerable. 

The Paper on this occasion was presented by Mr. Ernest R. Matthews, 
A.M.Inst.C.E., F. R.S.Ed., Borough Engineer of Bridlington. The paper was 
a very interesting one, and the discussion which followed also calls for favourable 
comment. We are giving a lengthy summary of both. 

REINFORCED CONCRETE CHIMNEY 
CONSTRUCTION. 

PAPER by ERNEST R. MATTHEWS. A.M.Inst.C.E., ER.S.Ed. 

[livroiigk Enginar of Bridlington.) 

Mr. W. T. Hatch, M.Inst.C.E., Metropolitan Asylums Board, Member of Council of the Conoete 
Institute, presiiei. 

MR. ERNEST R. MATTHEWS. Reader of the Paper. 

Thai reinforced concrete \va.s considered by .\nierican eng;ineers and .-irchitects to be 
siiil.nble for the construction of chimneys, the author suggested, mijjht be gathered 
from the fact that during the past seven years one firm alone had erected nearly a 
thousand such chimneys in .America, under the direction of some of the most able 
engineers and architects in that continent. 

He divided the subject-matter of this ])a[x;r into — (a) The advantages of using 
reinforced concrete for the construction of chimneys, (b) The erection of reinforced 
concrete chimneys in Great Britain, (c) .\ tabulated statement giving particulars of a 
number of these chimneys constructed in the United States, (d) The methods of 
calculating the stresses and strains in such chimneys, and reason for the recent failure 
of a shaft in the United States, (e) The effect of excessive heat upon concrete and 
reinforcement, (f) General notes with respect to reinforced concrete chimneys. 

Advantages of using Reinforced Concrete in Chimney Construction. — It had 

been found in .\merica that rL-inforced concrete chimneys could be built by a well-organised 
firm at less than one-half the cost of a brick shaft, and that the larger the shaft the 
greater the saving, since a large brick chimney of considerable height must have 
brickwork of great thickness at its base to prevent overturning. 

It was also usually found that in districts where brickwork was expensive concrete 
was also costly, so that there was no difference in the ratio of their respective cost. It 
would ap|)ear, therefore, that on the ground of econoiny reinforced concrete had much 
to recommend it as a material for the construction of chimneys. Saving of space was 
often a great consideration. In a shaft 300 ft. in height, for example, the brickwork 
114 



f J,tlON.Vll.'IK-HON 
Lt^LN(.lNI:-l^HlNC. 



2] 



COSCRHTH CIUMSEV CONSTRUCTION. 



;it (111' hasc, ;icc(>rilirii,' lo thu biiildiii},'^ nj^'ulallons of our lin>,'lish cities and l)(ir()Uf,'hs, 
would \w about 4 ft. 10 in., wheruas the thicUiifss of llii' walls at llic base of a 
r« inforceil-concrete chininey would probably be as follows: outer wall 9 in., inner wall 
5 in., with a space of 4 in. between the two walls. Therefore considerable economy 
of space was at- 
t.iinable by the 
eiiiploynieiU of 
reinforcetl con- 
crete for chijii- 
ney construc;ion. 
The weight w.is 
also less than a 
bricU shaft. 
which naturally 
arose from ihe 
savinjj of sp.Tce. 
a n d w a s a 
matter of the 
j^reatest import- 
ance where a 
treacherous soil 
had to be built 
upon. 

Reinforced - 
concrete chim- 
neys had been 
erected in the 
L'nited Slates 
for some years 
past, ;in<l thr 
author knew of 
only one failure. 
Reinforced con- 
crete lent itself 
admirably to 

chimney c o n - 
siruction, a re- 
commeiida t i o n 
which could not 
be so coniidently 
asserted with re- 
g^ard to brick- 
w o r k . T h !■ 
a u t b o r c o n - 
sidered that a 
reinforced con- 
crete chimney, if 
p r o p e r 1 y dc- 
sitjned, was ni 
ijreater stabili;\ 
than one built 
of brick, since 
the former had 
of the joints. 

Once erected, rein forced-concrete chimney shafts required practically no repairs, 
while steel-plate chimneys required paintinij about every four years, and brick chimneys 
occasionally required repairintf. The rapidity of e.xecution of work was well known; 
a reinforced-concreie chitiiney could be erected in half the time that it took to build a 
brick shaft. 




no joints, whereas in 



occur at anj 



THE CONCRETE INSTITUTE. 

These were some of the advantatjes 
which the author claimed for the use of 
tliis material in cliiinney con~truclion. 

Typical Examples of Reinforced- 
Concrete Chimneys in Great Britain. 
-Vl'he author then referred very bricth . 
before giving American examples, to one 
or two of the reinforced-concrete chimneys 
which had been erected during the past 
few years in this country. Several of 
such chimnevs might be referred to, 
but the object of the paper was to deal 
chieflv with those erected in the I'nited 
States, so that only a few were 
mentioned. 

Chinnit-y at .Messrs. Lyic c'-- Sons' 
Works, London, E. — I'he shaft erected a 
short time ago at the works of Messrs. 
Abraham Lvie &■ Sons, Ltd., of London, 
E., was a good example of what could be 
done in reinforced concrete. This chim- 
nev was 261 ft. in height and 20 ft. in 
diameter. The walls, for the upjx-r two- 
thirds, were <S in. in thickness, double 
walls being built in the lower third. 'l"he re- 
inforcement consisted of vertical bar con- 
sisting of ij-in. X ij-in. x t7;-in. T's 
and horizontal rings of |-in. steel rods 
spaced at i.S-in. centres, vertical bars 
extending into the concrete foundations. 

Cliimncys at Briton ferry, Glamor- 
gan, and at Kelfast. — The chimneys re- 
cently erected for the Cape Copper Co., 
Hriton Fcrrv, ( jlaniorgan, and for Messrs. 



[g^TCBETEJ 




Construction. 




View Showing Chimney in course of construe 



COSCRETI-: ClllMSEV CUSSTRUCTIOS . 



cic ;ils<) j{o<kI i'xani|jk"s. I he diincnsions wen- as 
diainctcrs of outer shells, \x ft. and 8 ft. 6 in. 



J. .V S. M. (Jrecves, Ltd., of Hdfa^l, \ 
follows : heights, 150 ft. and .'00 fi. 
respectively. 

Large Chhiuity al jViir//i//rc/.— This had recently heen erected; it was 8 ft. b in. 
inside diameter, and 247 ft. in hei),'lit ahove bottom of foundations, and was a fine 
ex.nnple of reinforced-concrete construction (see Hg. 1). The foundations, the bottom of 
which were 35 ft. below ,i,'round-level, were remarkably shallow, beinfj; only 2 ft. ta|XTinf;^ 
10 4 ft. in thicivness, .and i.S ft. x iS ft. in are.i. .\ b-in. liatlle wall w;is constructed across 
the lower |X)rlion of the shaft, ,uid the thickness of the shell up to b2 ft. above the 
j;round-level w.is as follows : outer shell, 12 in.; cavity, 4 in.; inner shell, 4 in. .\bove 
this the chimney consisted of a single shell y in. in thickness. The reinforcement in 
the foundations consisted of ij-in. x ij-in. x V^-in. T's, and in the shell of horizontal 
rings of steel | in. diameter, spaced iS in. apart, and vertical bars formed of ij-in. x 
I l-in. X A-in. T's. higs. 2 .and 3 show the larger chimney in course of construction. 

Smaller Cliimncys al Xdrllitlvcl. — .\lthough .1 smaller chimney, ijo ft. high, the 
one recently erected .at the Kijighi, Hevan .ind .Sturgc Works at Xorthfleel (see big. 1) 
w.is of much interest. The sh.illow depth of the foujulation was rather remarkable. 
While this w.as 15 ft. (1 in. square in area, the depth was only 3 ft., ta|x>ring to 2 ft. 
The inside diameter of the chimney was 5 ft. The bottom of the fouiul.-ition was 16 ft. 
br-low ground-level, .and this w.is reinforced by ij-in. x i}-in. x-ft-in. bars. For a height 




Reini-'okced Conxrkte Chi: 



of 41 ft. above ground-level the outer shell was 6 in., the inner 4 in. in thickness with 
a 4-in cavity between; q-in. diameter air inlets occurred at interv.ils; above this the 
chimney consisted of a single shell only 5 in. in thickness. The shell was reinforced 
by means of vertical bars and horizontal rings, the former being deflected around 
smoke flues. The vertical bars consisted of ij-in. x ij-in. x -re-in. T's, the rings 
being j in. di.ameter steel rods placed iS in. apart. .\t the bottom of the offset flat 
rings 3 in. x A in. were inserted. Fig. 5 shows the smaller chimney in course of 
construction. 

The two foregoing shafts had been erected for the .Associated Portland Cement 
Manufacturers, at their works at Xorthfleet. 

The author then gave e.\.amples of various reinforced concrete chimneys which 
had been erected in .\merica. 



THE CONCRETE INSTITUTE. 



[CONCRETE! 



Methods of Calculating Stresses in Reinforced Concrete Chimneys. \\\th 

regard lo the recent failure of a chimney in tlie L'nited States the conckisinn^ arrived at 
In-' the authors of an article on "The Design of Reinforced-Concrete Chimneys," 
which appeared in Engineering in March, i<)iiS, were interesting and instructive. 'Hiey 
said : — 

'"It would ap];ear, therefore, that wliile the thickness of concrete was ample, 
there was not nearlv enough steel to ensure safety, and, of course, this deficiency in 
steel greatly increased the pressure on the concrete by throwing the line of zero stress 
away froin the centre of the chimney, and thus leaving a very small proportion of the 
section in C(Hn|>rei.sion. . . . The failure of this chimney cannot be said to cast any 
reflection tipon the u>e of properly designed reinforced concrete for such structures." 

Effect of High Temperatures — In order lo obtain some reliable data regarding this 
important matter the author determined to carry out two series of tests- one dealing 
with concrete that had only had a short set, the other with concrete that had at least 
two months' set- and he gave detailed particulars of these tests. 

The author determined to obtain some 
informalion regarding the condition of the 
concrete and reinforcement in an existing re- 
inforced concrete chimney, and he acknowledged his 
indebtedness to Mr. H. K. G. Bamber, F.I.C., of 
the .\ssCK-iated Portland Cement Manufacturers 
(iqoo) Ltd., who kindly supplied him with some 
most useful information on this subject. 

Mr. Bamber informed the author that in order 
to ascertain if concrete deteriorated through the 
effects of heat he inspected on several occasions the 
face of the concrete shell inside the reinforced 
concrete chimney at the works of his firm at North- 
lleet, and he failed to observe any signs of deteriora- 
lion. Not contenting himself with this, he sub- 
iictcd the ash in this chimney, on various dates, to 
an analvsis, and compared this with an analysis of 
;he ash taken from the base of a brick Custodis 
~haft, also at his firm's works at Northfleet. The 
comparison was most interesting ; there was very 
little difTerence in the percentage of insoluble residue 
;)rcsent, which residue would, of course, include any 
portions of sand that might, from deterioration, be 
coming away from the inside of the inner shell of 
the concrete chimney. 

Mr. Bamber kindly had a small hole cut out 
lor the author in the base of the inner and outer 
shells of the reinforced concrete chimney at North- 
fleet for the purpose of exposing- a portion of the 
reinforcement. These were made just ov-er the 
flue opening where the heat would be most likely 
to affect the concrete. The result was most satis- 
factorv, the steel being in as good condition as when 
first inserted in the concrete. 

The author's experiments led him to the follow- 
ing conclusions : — 

(i) That neat cement behaved better under great heat than out of it. The average 
compressive strength of 2j-in. cubes placed in flue for 28 days, after having remained 
in air for 14 days, was 52-6 tons on the cube compared with 3^,-6 tons when placed in 
water for a similar period; the tensile strength per sq. in. of the briquettes being 
1,008 lb., compared with 850 lb. in the water test. 

(2) That concrete {3 parts standard sand to i part Portland cement) if not well 
set behaved very badly under heat. Tlie average tensile strength of briquettes i-in. 
section (3 to i) placed in flue for 28 days, after being in air for 14 days, was 105 lb., 
compared with 310 lb. at 7 days, and 4(x) lb. at 28 davs in water. 

118 




[Z-SoSI'^Tno^ concrete chimxey cosstructiux. 

( i) I liat if llu; c'DiRTctc hatl hail at least a two-iiiontlis' set before heal was applied 
a temperature of 900 <i<.'^. Kahr. would not alTecl It in the least. This might he taken 
as the safe teinix-rature in rein forced-concrete chimneys. 

(4) 'I'hat the 3 to i s|x;cimens in these tests givin;^ such (xwr results pointed to 
the necessity of havinij no voids whatever in any concrete work, it beinj^ well known 
that 3 to 1 briquettes ni.ide of standard sand contained a considerable quantity of air 
spaces 

(5) That only nllowini; the specimens 14 days before subjecting them to the heat 
was far too short a |X'riod in .actual work. The greatest advantage w.is obtained by 
letting the heat get at the concrete after the longest time has been given for the cement 
to set. 

(()) Concrete mixed with 10 per cent, of water (which should be the ma.\inium in 
work of this class) would contain only about 1 per cent, of free water .after a two- 
months' set. He.it should not be applied to concrete until the latter had had a two- 
months' set, a longer set than, say, three months would be preferable. 

Generally rcinforci»d-concrete chimneys had been objected to on the following 
grounds: (1) because occasionally during the hardening of the concrete hair cracks 
have been noticed on the concrete surface, and it h,-id been thought that these may 
affect the temperature in the chimney and consequently the ilraught ; (2) because 
chimneys constructed of this material were, in the opinion of some, unsightly. 

With reg.-ird to the lirst objection, the author admitted that hair cracks did fre- 
quently occur when a large concrete surface was setting, but these were only skin 
deep, and in the case of a chimney could not |x)ssibly affect the internal tem[X!rature. 
As to the second objection, there was no reason why a reinforced-concrete chimney 
should be unsightly; it could be made ornamental if required so, and at no great 
extra cost. 

The aggregate in the concrete in the case of chimneys was fine, but coarser 
material was used in the foundations. .Ml concrete was well tamped. The factor of 
safety use<l by well-known chimney builders in .\mcrica was between 4 and 5, and 
provision was frequently made for stresses which would be set up by a inaximum wind 
velocity of 100 miles an hour, a velocity which was pr.ictically unknown. It had been 
the custom both in Great Biitain and -America to take the maximum wind pressure at 
50 lb. \xr sq. ft. on a square shaft, and half this on a circular shaft. 

No tensile stresses on the concrete were allowed for. The chimneys were well 
anchored by continuing the vertical steel bars into the foundation and then bending 
them through 90 degrees. The large number of vertical bars in the outer shell was 
<livided into two portions, one-half of which were bent to reinforce the upper part of 
the foundation slab, and the other half, which alternated around the chimney, were 
bent at the bottom of the slab. .Ml of the vertical bars in the inner or expansion shell 
were carried down into the foundations and bent over. Continuitv in the steel was 
provided by overlapping the ends of the bars at least 30 diameters. .Ml wind stresses 
were provide<l for by the vertical steel reinforcement and temperature stresses by the 
horizontal rings or plain round rods (as already described) bent to a true circle. These latter 
were spaced not more than iS in. apart vertically, and, as in the case of joints in the 
vertical steel, the breaks in the bars were staggered so as to occur unevenly and form 
no plane of cleavage. .Additional ring steel was placed at any bends in the vertical 
steel, as at the offset and foundation. In designing a chimney the stresses were 
computed at several sections. 

The foundations were frequently reinforced by two meshes of steel bars as already 
explained, tlie top mesh running at right angles to the side of the foundation for its 
full width, the bottom mesh consisting of bars laid diagonally in each direction at an 
angle of 45 degrees from the side of the foundation. .Additional vertical bars should be 
placed on the sides of the smoke opening to take the place of those omitted in that 
opening, and .-idditional bars ])l;iced above and below the smoke opening to furnish 
lintel and sill reinforcement. 

The forms used in the construction of reinforced chimneys were necessarily some- 
what complicated and intricate. 

The Chairman then called upon Mr. William Dunn, F.R.LB..4., to open the discussion. 

MR. WILLIAM DUNN. F.R.I.B.A. 

Failures, — There was no doubt that reinforced concrete was a suitable material for chimney 
construction. There had been failures, but these failures had been from faulty construction "or 

119 



THE CONCRETE INSTITUTE. raVCBETEJ 

design, from defects which could be controlled. He noted that .Mr. Matthews only knew of one 
failure, but in the investigation made by Mr. Sandford E. Thompson for the Association of American 
Portland Cement Manufacturers in iqo7 (which, if he remembered aright, was an investigation into 
some 400 chimneys which had then been built\ he mentioned more than half a dozen complete 
failures — blown down, or fallen down, or torn down because of their defective condition. He said 
thst the total failures were about 2 per cent, of the chimneys reported on ; another 2 or 3 per cent, 
were of doubtful safety, which, of course, was a very high percentage of failures in chimney building. 
This, however, was in the very early stage of reinforced concrete chimney building, and the American 
builders of such chimneys had no doubt learnt something from bitter experience. 

He had built a brick chimney about 130 ft. in height some ten years ago, and it was in use 
but a very short time when he was informed that it had badly cracked. He examined it and found 
this to be the case, but the cause w'as not due to any defect in the design of the chimney ; it was 
due to excessive heat from the boiler flues. The temperature of the escaping gases at the base of a 
chimney should not exceed .soo' to 600°. In this case an automatic stoker had been fitted to the 
boiler, the coal supply had caked, and the supply of oxygen was insufficient for proper combustion. 
He found the temperature at the base of the shaft about 1,400", in place of some 400° to 600°, which 
would have been the temperature with proper stoking. When the stoking was put right, and the 
heat reduced to ordinary temperature, the cracking ceased. Brick chimneys, as the chairman had 
said, usually showed cracks. It would be strange if they did not, as the temperature inside was 
so much above that outside, especially when there was a gale of wind and sleet. The inside lining 
in the lower part was a protection, but the temperature all up the shaft remained high : indeed, it 
was only about 20 per cent, or 30 per cent, less near the top than at the bottom, so that at the 
top of the inside lining, where the shaft was not protected, one would expect to see cracks. From 
photographs of reinforced concrete chimnevs which he had seen both horizontal and vertical cracks 
were to be found which were sufhciently alarming but not necessarily dangerous, .^t that point 
there was also usually a reductioti in the diameter of the shaft, and special care was reqpired with 
the reinforcement. 

Weight of Chimneys.— ^h. Matthews mentioned the lesser weight of reinforcd concrete chimneys 
as an advantage. So it was in some ways, but not in all. For instance, in considering the stability 
of the chimney, the effect of this lesser weight on the stresses in the steel and concrete was very con- 
siderable. The greater the weight of the chimney in relation to the exposed siurface the less the 
relative effect produced by the bending moment due to wind. In a well-designed brick chimney 
there was no tension on the windward side, as brick cannot resist tension ; but in a reinforced con- 
crete chimney one might perfectly well allow the line of action of the wind and dead load to cut 
anv horizontal section beyond w-hat was called the kern — that is, the part which corresponds to the 
middle third in a plain square section — as the steel reinforcement took up any tension. That was 
a very fortunate thing, as otherwise a reinforced concrete chimney would have too little weight to 
prevent tension on the windward side. 

Temperature.— One difficulty in chimney design was that one was obliged to proceed by trial and 
error, as in the case of arches, adopt a design and test it for stabihty. Assuming the stability of the 
chimnev, there remained the question of its durability. The durability was largely a question of tem- 
perature. It appeared from experiment with tubes, such as had been described by Mr. Matthews, 
and from experience with actual structures, that temperatures of 400' to 600°, such as were usually 
met with at the base of chimneys, did not injuriously affect gravel concrete. It was only after a 
temperature of 750° or so is reached that injury resulted. This left a comparatively small margin 
in case of excessive temperatures. Of course, concrete formed of limestone should ne\ er be used for 
work exposed to great heat. The tests made by Professor Norton had shown that limestone concrete 
begins to lose strength at temperatures under 500". Mr. Matthew-s' experiments were made with 
concrete with an aggregate of clinker exposed to fire, but actual experience with chimneys was 
worth more than laboratory tests, and we were \'ery much indebted to Mr. Bamber for his exceedingly 
interesting report upon an actual chimney. Mr. Bamber is a careful and accurate reporter, and 
very great importance should be attached to what he says. 

Coasisteacy of the Concrete.— One or tw'o points not mentioned by the speaker occurred to him. 
One was that a slightly wetter mixture than usual was desirable to secure proper adhesion to the 
bars, though Mr. Matthews would rather limit the water used. Proper adhesion to the bars was a 
very important thing, and the failure in some of the .American chimneys investigated by Mr. Thompson 
was due to want of adhesion between the concrete and the. steel. 

.Another point was that circular rods seem preferable to T bars for the reinforcement, ow-ing to the 
special care required in tamping the concrete round T bars to secure adhesion. Then there was the 
question of time ; Mr. Matthews had told them that there was a saving of about half the time. Person- 
ally, he would not like to claim that advantage for reinforced concrete chimneys. In all chimneys 
the rate of execution is limited to a few feet in height per day. It was specified that there should 



( &^im"^mN?^ CONCRETE CHIMNEY COXSTRUCTION. 

H-t 1h- [,■ tli.m .1 Ifu tc-cl 111 h<-i^lu |.r. cl.iv. .ma lir ilMul.IrJ ih,' wisd. .m .,f j-oiTig furtluT with 

ri-iiilorn-il (oiuri'tc tiiiiii lirickwoik 

MR. C. PERCY TAYLOR. A.M. Inst. C.E. 

He thought this subject should he looked upoji honi two rather distinct points of view. The 
ru>.t was purely a matter of the chimney as a structure, and when one considered that all the stresses 
that the structure had to bear were due first to weifiht, and secondly to bending due to wind, they 
would a^rce that reinforced concrete was an ideal substance for chimney construction. 

Temperature Tests.— The more important point of the discussion seemed to him the question of 
heat. The author had given them the results of a good many tests which had been made on samples 
placed in flues, but he thought he was right in saying that none of the samples had been tested after 
being more than 38 days in the flue. He did not think that was really nearly long enough to give 
.any satisfactory and reliable result. He had been making for some time experiments with samples, 
and had some in the line up to 15 months. They were made with a 3 to i mixture, rotary cement 
and sand, not standard sand. Some of these samples were still in the flue, but up to the present 
he found that the 2] cubes could be relied on to stand a stress of 3,000 lb. to the sq. in., and that 
seemed \ery constant, as similar material mixed in the same way would go much higher, to about 
5,000 lb. in air, but it was subject to rather violent variations, to which nearly all concrete is subject 
when tested for long periods. The residts of the cubes in the flue were very much more constant at 
about 3,000 lb. to the sipiare inch. The tensile results were not what one would call good. They 
came out at an average of about i.to lb. per sq. in. The question of tensile stress did not really come 
hito the design of a chimney or any other concrete structure ; but, in his opinion, it indicated — as 
there must be some connecti m between tension and sheer — that one ought not to rely on a concrete 
chimney taking any sheer, whatever one might consider in an ordinary structure not subjected to heat. 
While the cubes and tensile samples had been in the flue, they had had some bars 5 in. square, 
with brass plugs let in on all four sides to 33', in. centres as a convenient length, and his friend .Mr. 
<.lenday had been measuring them very carefully by periodically taking them out of the flue to see 
whether .any change of length took place. They had had some of the bars plain, and some reinforced 
with I in rods. The result of these tests was rather peculiar. They found that when the sample 
was put in the heat and measured after seven days, there was in the plain samples a very marked 
contraction amounting to about a twelfth of i jier cent., but when the samples were reinforced the 
bars had the effect of reducing that contraction to very much less. The difference between the plain 
sarhples and the reinforced samples amounted to about one-twentieth of i per cent. He had been 
seeking an explanation of the dilTerence. It appeared obvious at first sight that it was due to the 
bar holding the concrete in what he might call an elastic way, but if one assumed that the concrete 
had really wanted to shrink, and had been held to its normal length by a steel bar, it must have pro- 
duced a tensile strain in the concrete of something like 2,000 lb. to thesq. in., Snd it must necessarily 
have cracked. .\s a matter of fact, although there might be minute cracks, he had not found any 
■when he cut up the bars himself with a hammer and chisel, and he thought that the bars had in some 
way the power of preventing the concrete contracting. He wanted to explain that it was not simply 
holding it with a tensile strain, but preventing it contracting at all. The fact that these samples had 
not actually visibly or app.arcntly cracked showed, he thought, that the heat did not of itself tend to 
crack the concrete. He was not here referring to the temperature gradient through the shell which 
put an actual stress on the material. 

Bond Tests.—MteT these samples had been used for taking these measurements, some of them 
were used for bond tests. The samples were cut in halves, leaving a portion of the bars in each 
end of the concrete block, and the two ends were then pulled apart. The samples were not reallv 
prepared for the test, and the fact that there were four bars made it quite impossible to secure .ui 
equal stress on them all, and the results were very variable indeed, the surface adhesion varying 
from 20 lb. to 370 lb. per sq. in. ; but they found in one of the samples that it had been accidentally 
cracked, one of the 20-lb. ones, and in another of the bad ones the bond was very bad indeed. He 
put that down to the stuff being made up too dry. It was made up by an extremely careful and 
experienced man, but he entirely failed to get a good bond, and he thought that was a verv strong 
reason against using dry concrete. C.enerally speaking, although some of the results were bad, he 
thought that with wet concrete well rammed round one would be able to rely on using for practical 
purposes a bond of 50 lb. per sq. in. 

Crac*s.-The author had restricted himself entirely to what he called "hair cracks which had 
developed during the hardening of the concrete." Now, he (Mr. Taylor) thought he might sav the 
cracking of the chimneys was really the one thing which had retarded their adoption in this country, 
and it had to a certain e.xtent retarded their use in .America. .Mr. Thompson, as Mr. Dunn had 
pointed out, had investigated this matter very closely indeed, and he had come to the. conclusion 
that with proper distribution of horizontal reinforcement all cracking could be entirely avoided, and 
he (Mr. Taylor) also thought that the stresses produced by the temperature gradient through the shell 

I 2 1 



THE CONCRETE INSTITUTE. [^^CBETE] 

could really be subjected to matheuiatical treatment. He alio thought that the cracks could be very 
much reduced, or, at any rate, made \'ery much less severe, by the use of some sort of deformed bars. 

Mr. Dunn had mentioned the objections to T bars. He thought that objection was very well 
fotmded. He recently cut two holes himself in the large chimney at Northfieet, where there were 
cracks, and he thought that the T bar was much too big for the amount of steel. It tended to cause 
a bad crack, where a round bar probably would not have such a bad effect. It was interesting to 
state that, though this crack was J iti. wide and only J in. deep, the steel they came on was absolutely 
sound, and there was not a sign of corrosion of any sort in either of the places where they cut into it. 

Consistency of the Concrete.— .\s to specifying lo per cent, of water for use in the concrete, he 
thought it was a very bad practice to specify an amount. It must differ with the cement, and the 
sand, and with the weather. What they wanted to get was a quaking concrete which could be 
rammed round the bar, a little water showing at the top when one had finished ramming — this was 
to say, wet without being too sloppy. 

L/n/nis.— With reference to the question of linings, anybody who had watched a concrete chimney 
being built must have realised that the building of the lower lining concurrently with the outer shell 
must cause considerable expense and delay. The air space between the two was only generally four 
or five inches. Into that space one had to get the inner shuttering for the outer shell, and the 
outer shuttering for the inner shell, and it was obviously impossible to build the next length until 
one had taken the shuttering out of the previous length. That, as a matter of fact, caused a con- 
siderable delay. He thought it would be far better to build the chimney up without any lining at 
all, and to put that in afterwards. It could be put in quite well by building slight recesses about 
every .30 ft., much the same as in a brick chimney. If a slight recess was built in the shell a little 
extra reinforcement could be introduced if necessary, and either blocks or concrete rings put in 
afterwards. Spaces could lie left behind to allow for expansion. He thought it was a mistake to 
stoj) the lining one-third of the way up. The temperature of gases, as Mr. Dimn had pointed out, 
was practically the same all the way up ; they cooled very little. There was just the same necessity 
to line the top as the bottom, except for one reason, and that was that the bottom had to be 
thicker than the top, and a given temperature must necessarily produce greater stresses in a thick 
hning than in a thin one ; but, except for that difference, the lining, if wanted at all, must be 
carried to the top. 

MR. JAMES LYLE. 

They had built a reinft»rced concrete chimney 2O1 ft. high b\' 20 ft. diameter, and they had got 
some cracks in it. He thought that the shuttering used for the flue openings was not stiff enough, and 
that this part of the chimney should have been made a little thicker all round, and circular, by 
means of usual moulds, which would have made a much better job. 

MR. W. JOHNSON (Engineer to Messrs. A. Lyle 6 Sons, Ltd.). 

Tests on B/otAs.— ."^^ter listening to Mr. Matthews, he also was struck with the short time he had 
allowed the test blocks to remain in the flues. Before Messrs. Lyle decided to build a concrete 
chimney, they made several blocks about 3 ft. square by 6 in. thick They reinforced and made 
them in a similar manner to ordinary reinforced concrete with small ballast, mixed very wet. Those 
blocks had been in the flues, and subject to about 600° to 700° Fahr. for ji years, and the concrete 
was practically destroyed. He knew that there was very httle difference in expansion between steel 
and concrete, but there was some ; and it was his opinion that this had had some effect on the concrete. 
In examining these blocks they found right round them, in the same plane as the reinforcement, 
definite fractures, not air or surface cracks. 

Messrs. Lyle also made two blocks 2 ft. by 2 ft. by 8 in., with an aggregate of sand and cement 
(32 to i) mixed diy, and reinforced like the chimney. These blocks were well rammed. They had 
been in the flue 2i years, and there was no comparison between these and the blocks they mixed wet. 
He did not .-"grec with Mr. Thompson in his report on the .American chimneys, that the concrete should 
be wpt. He thought that a deformed bar should be used, and the concrete should be made, con- 
sistently with a good job, as dry as possible — with just a little moisture coming to the top, and that 
this concrete would stand heat much better than concrete which had been mixed wet. 

Cracits.— After their chimney had been erected 12 months, they scaffolded up the inside, arid 
examined the lining. They swept off the soot, which was about J in. thick for a height of 90 ft., and 
found at the offset about seven or eight cracks, definite fractures. They varied from ^ in. to /j in. 
in width. They had not the same number of cracks on the outside as on the inside. They had 
about three or four on the outside, and these were much smaller. They had been up to the offset 
on the outside. He went up the scaffolding on the inside, and by a cradle on the outside, and 
examined the chimney at the offset, and he was speaking of what he had seen. 

Lining of Chimneys.— ^^^ reference to the lining, he thought this should be built after the body 
of the chimney, and it[shou!d be quite separate and apart from the outside shell. The expansion on 

I 22 



[ », CONM'UIJ(.T10NAlJ 

\K. E^K,lr^lL■E^^l no ^ 



CONCRETE CHIMNEY COXSTRUCTIUN. 



l!io iiiMili- shell w.is ureal, and il bniiiglU iiiti) (■(■iitact «ilh the miler sh'-ll, as Mr. Taylor sii(;t:esle(l, it 
would destroy the outer shell. If he were building a chimney aRain, he would take the linini; to the 
top, and allow an air space of not less than lo in. to 12 in. A pood inanv ducts shoi'ld be made through 
the outer shell, so that air ct)uld pass freely into this space and keep the outside shell cool. Th-iir 
inner shell was in a bad condition, but quite safe. 

He thought the method of putting in a thick offset was wrong. The big mass of concrete and 
variation in diameter at that point causes unequal expansion in the chimney. It should be taken 
parallel from the top to the bottom, and with as little variation in the thickness as possible. 

He did not believe in orTiamental chimneys. By putting fancy shapes round the top and altering 
the symmetry of the chimnev, trouble w.ts brought in. If it were kept parallel, straight, and as equal 
in thickness as possible, it would give less trouble. 

He had no hesitation in saying that if a reinforced concrete chimney were properly designed and 
properly built, it would be a good chimney. He thought there was as much in the building of a 
chimney as there was either in its shape or the material that was put into it. .'V responsible man 
should be on the chimney the whole of the time from start to liuish, because so nnuh was left in the 
hands of the men putting it up. and if one mistake we-e made the chimney would be faulty. 

MR. ALFRED W. BROWN, A.M.I.Mech.E. 

Oenera/ty.— He was a thorough htlie\er iu reinforced concrete for almost every class of construc- 
tional work, but was not incline<l to think niuforced concrete suitable for the peculiar conditions 
of stress existing in a chimney. 

There was first "an alternating temperature," sometimes changing from 1,500" Fahr. to 300° 
Fahr. in a very short period (say, in destructor chimneys, boilers with oil firing, or baking ovens) ; 
secondly, the inside of the chimney shell w is hot while the outside was cold, and sometimes wet as well ; 
and, thirdly, the whole structure swayed somewhat in a wind, so that the sides were alternating 
between tension and compression all the time, in addition to the stresses set up by the changing 
temperature inside the chimney 

Mr. Matthews laid some stress on the saving of space, but he (Mr. Bmwn) thought it was com- 
paratively rare that the amount of space saved by a concrete chimney was a consideration, as chinmeys 
are, especially the larger ones, often outside the works altogether. Mr. Matthews also mentioned 

4 ft. 10 in. as the thickness of a brick chimney 300 ft. in height. He thought that 3 ft. 3 in. would 
be found sufficient for a scientifically designed job. He thought Mr. .Matthcws's experiments hardly 
conclusive enough as regards the behaviour of reinforced concrete for chimney work, as all the 
various blocks had been exposed to the heat on all sir sides, while the chinmey was exposed mi one 
side only, which was a much more severe condition. 

In his " Conclusions " Mr. Matthews stated " that if concrete has had at least two months' set 
before heat is applied a temperature of ooo"" Fahr. will not affect it in the least. 77i!.s might bf taken 

05 the sale Icmfteralitre for concrete chimneys." If this was the safe temperature for concrete chimneys 
he was afraid that their scope was somewhat limited, as chimneys for destructors, baking ovens, blast 
furnaces, and oil-fired plants had to withstand a temperature of 1,500° Fahr. 

He thought Mr. Matthews's wind stress allowances were too empirical. He had computed the 
pressure on a round shaft as Imlr the pressure on a surface at right angles, whereas it was nearly 
■66 of this amount, the correct formula being : — 
P = V^ X -66. 

Where 1' = Pressure of wind in lbs per sc]. in. 
V = Velocity of wind iu miles per hour. 

MR. OSCAR FABEK. B.Sc, A.C.G.I. 

T/ilckaess ot Chimneys.— With regard to the design of chimneys he would like to point out the 
desirability of keeping the thickness of the chimney as small as possible. This could be seen by 
the formula on one of the diagrams, which gave the thickness of concrete and the quantity of steel 
required in a chimney for given conditions of wind pressure and stress in the concrete and steel. 
It was easily, shown from that that it was cheaper to stress the steel 'at a low unit stress and put a 
comparatively large quantity of steel in the shell, and then make the shell thin, than to adopt a thicker 
shell with a lower percentage of steel. They could design a chimney first of all with a fairly thick 
ring and see what quantity of steel had to be put in, and then design the same chimney with a 
Uiiii shell and more steel, and work out the cost of the two chimneys. It would be easily found 
that it paid to adopt a thin wall. 

The chief practical difficulties in making a successful concrete chimney were to prevent the 
chimney from cracking, and there was no doubt whatever that the thinner the wall was made the 
less tendency there would be for the concrete to crack, due to temperature stresses. The temperature 
stresses depended entirely on the difference of temperature between the inside and the outside of 
the shaft, and the thinner the shell was made the smaller would be the difference. 

Cracks la CA/mneys.— There was a point where the experience of the Associated Portland Cement 

E - 123 



THE CONCRETE INSTITUTE. [CONCRETE] 

Manufacturers, who have three chimneys, was different from that oi Mr. Johnson, and that was a^ 
regards the position of cracks. In the chimneys at Northfleet of the Associated Portland Cement 
Manufacturers, in every case the tendency was to crack at the outside of the chimney much more 
thau at the inside of the chimney. One would expect, the inside being hotter, that it would expand 
more than the outside, and consequently cause cracks on the outside. It was very curious that 
the chimney at Messrs. Lyle"s works should have cracked in exactly the opposite manner. 

Mr. Johason: He would like to know if Mr. Faber had been up to the chimney inside at the offset ? 
Mr. Faber: He had, and they found hardly any cracks inside, even at the offset. Why he men- 
tioned this point was because he thought the most useful object of any discussion like this was 
for everybody to add their experience together to see exactly where they differed. These difier- 
ences suggested that temperature stresses were not the only ones which determined these cracks. 

If cracks were more likely to occur on the outside, which was the experience in a large number 
of chimnevs, then it was better to put the reinforcement near the outside of the chimney rather than 
at the centre of the ring, because reinforcement then prevented with much greater efficiency those 
cracks from taking place. He would just like to add, if possible, to Mr. Taylor's suggestion that 
t he inner shell of a chimney was made much more effective if one let a cold draught through it, and 
therefore he suggested that, in making a shell in several pieces, perhaps it would be possible to 
leave small holes through the outside shell at the base of each section of lining so as to induce a 
cold draught to go up through these spaces and keep the temperature of the outside shell lower than 
it otherwise would be. 

Stresses.— .\nother point was that their formula gave a means of determining stresses 
from statical conditions only, but in his opinion the stress in concrete chimneys was determined 
\ery largely simply by temperature and shrinkage stresses, and therefore it was always advisable 
in concrete chimneys to take fairly low unit stresses, because these temperature and shrinkage stresses 
made the conditions somewhat indeterminate. .•\lso, in the case of chimneys, very little sacrifice in 
the wav of economy was necessary in the adoption of low' stresses, as explained before. 

Bars for Reinforcement.— .Ks regards the adoption of the deformed bar, he thought a deformed 
bar would be excellent for the circumferential reinforcement, because there was no doubt that with 
a deformed bar one tended to prevent large cracks appearing in a few places, and either one got no 
cracks at all, or there was a large number of very small cracks distributed throughout the length of 
the bar, which was' an advantage. But personally he did not think it was good to use a deformed 
bar for the vertical reinforcement of chimneys, for the reason that when the concrete had been put 
into mould and was setting, there was, during the first day, a very considerable contraction, and if one 
had a deformed bar there was a tendency for it to prevent that contraction taking place, and for that 
reason the concrete would not become so dense as it would be if it were allowed to contract during 
setting, and when a chimney was subsequently heated, there would be a greater tendency to crack than 
if one had adopted the plain bar and the concrete had partially slipped while it was contracting, 
innncdiately after it had been placed in position. 

Mr. Johnson mentioned that he thought the difference of expansion between concrete and steel 
had something to do with the formation of cracks, but he (Mr. Faberl suggested that the cracks were 
caused more by the contraction of the concrete than by any difference of expansion between the steel 
and the concrete. He was aware that the concrete in chimneys, and, in fact, all concrete kept at a 
high temperature, cracked more than other concrete, but he thought this to be due to the contraction 
being accelerated, and not to temperature stresses. 

Mr. Johason: He referred more particularly to the reinforcement of the blocks in their fiues : he 
had not in mind the fractures in the chimney. If anyone saw the blocks and the position of the rein- 
forcement, he did not think there would be any doubt in their mind that the reinforcement had in 
some way or other caused the fr.ictures. The cracks followed the line of the reinforcement so regularly 
that he could not help thinking that that was the cause. 

Mr. Faber: He acknowledged that concrete kept hot did crack more than when kept cold, but he 
attributed this to the accelerated contraction of the concrete. The steel caused cracks by preventing 
this contraction from taking place. If the concrete were unreinfnrccd, no stresses woiild be caused 
bv the contraction, and no cracks would form. 

MR. E. FIANDER. ETCHELLS, F.Phys.Soc, M.Math.A<'Soc. 
Comparison of Thickness.— One of the later speakers referred to a scientific design of a chimney 
300 ft. high with only about 3 ft. 3 in. of brickwork at the base. That design must have been 
scientific, but it did not take into accoimt the available floor space, because a chimney having 
walls only of that thickness would require a greater width of base than a somewhat thicker shaft. 
The author this evening mentioned 4 ft. 10 in. thickness of shafts. In the County of London 
they were bound by the Building .^ct of 1S04, which requires a rather greater thickness still. 
There is a very simple rule which will give the thickness required. 

124 



a7,i'r!,S',!S;;t^l CONOR HTE CHIMNEY CONSTRUCriON . 

I - I " 111.- >ii(»i/),-;- ,.l half brirks in tin- tliickiicss i.f the base ..f the shaft 
'- lh<' hntiht of the shaft in feet. 



Ihi 



■77,^1 



I'ur example, in the rase .if the iod ft. shaft >i =i6 half liricks =.S brirks =72 in. =f. ft. .if briek- 
wiirk at tlle has.' iif the shaft. 

Comparison nf Stability. Vhi- autli..r had said he considered "a reinforced concrete chimncv, 
if pr.iperly designed, was of i^recih'r staliilily than one bnilt of brick, since the former had no joints 
whereas in a brick shaft faihire niiKht occnr at any of the joints." But to be fair between the 
two methods of construction, yon shoukl permit the brick shaft to also be properly designed. 
I laughter.) Then, if it were jmiperly designed, there should be no tension at the joints, and no 
tendency t.i failure by rupture at such joints. 

Time Required tor Brectloa.— The author furthir said that a reinforced concrete chimney could 
be erected in half the time rcjuiri'd for a bri. k shaft, but t.i that half time the time required for 
the concrete to set must b • adde.l. 

Ratio of Hilght to DIameter.-WUh regard t.i the tables of the .himneys the author gave one 
200 ft. high and 7 ft. diameter. That meant th.at the ratio of height t.i its width was about 28. 
Under the Building .Acts iprobably throughout the Kingdom' a rati... if 12 was the maximum. There, 
of course, reinforced concrete had an advantage, but steel also had that advantage. He h.ad designed. 
or inspected, or erected at least 40, and they all exceeded 12 diameters in height. 

Line of Zero S/res».— There was a reference in the paper to the defuiency in steel greatly increasing 
the pressure on the c.mcrete by throwing the line .if zero stress away from the centre of the 
chinmcy. The line referred to is obviously the neutral axis of the cross-section. It should be 
noted that the method .if finding the neutral axis diflfers from the method in the U.I.B..\. Keport. 
In the paper on ■' Chinmcys," the p.isition of the neutral axis was apparently made independent 
of the ratio of steel in tension to concrete in c.impression. but dependent upon the stress, and 
th.refore upon the loading. In the 1M.B..A. Report the neutral a.\is dependeJ upon the percentage 
of reinf.ircement, but was independent of the load applied. This method of finding the neutral axis 
was \ery simple, and very ingenious. 

Recove/y ./ Concre/e. — Concrete seems to be a very human material after all. It will be 
noticed that it occasionally gets prostrated by the effects of prolonged heat waves, but a month's 
hydropathic treatment seems to bring it all right again, (Laughter i It mav n.it, however, always 
be cmvenicnt t.i plug up the bottom of the chimney and hll it up with water to keep it in a fit 
and proper state. 

Diaamlcs of a Chimney. — .A certain amount of discussion had arisen with regard to the tempera- 
tures and the question of air spaces or openings in the outer shell. Sometimes for the sake of 
convenience a chimney was placed rather a l.mg distance from the boiler.' This had the effect of 
cooling the flue gases .and incidentally reducing the temperature and draught of the chimney. 
Speaking only from the structural point of view, it would undoubtedly be an ad\antage to have 
openings in the outer shell so as to keep the shell cool, but the mechanical engineer or the electrica' 
engineer would have something to say about that. His whole aim is to get what he calls a good 
chmmey eflect. Supposing he has a natural draught, he wants a good velocity of gases. The 
velocity of the gases through the shaft w?s dependent upon the.diflerence of temperature between th? 
inside and the outside. If he began to get air openings in the side here, he reduce! the tempera- 
ture of the gases and reduced the chimney effect, and thus reduced the power of the chinmev as 
a draught-producing nuu bine. 

Effect of Heat on Steel. — If they had <)oo' Fahr. temperature on the inside of a j5himney shaft' 
and about, say, 60 odd on the outside, in between the two there was a tcmperattire gradient. 
Suppose the mean temperature to l)e about (00° Fahr.. the steel might stand, but sieel at a higher 
temperature than this would suffer a reduction of strength. 

Safety Factor — The paper stated that the factor of safety used by well-known chimnev builders 
in .Aincri.a was between 4 and s. He thought that it ought to be distinctly understood that that 
safety factor could only apply to the transverse resistance of the shaft, not its ni.iment of staliilitv 
about the base. It was a moot point whether that was really the safety factor of the chimnev. 
.A much more suit.able figure, perhaps, would be the moment of stability divided by the over- 
turning moment. Then, .if course, your factor would be nearer 2 or li. In fact, in some of 
these chimneys it may be even less than that. They had not seen the drawings at close quarters, 
but he was afraid that some of those chimneys have had sand filling at the bottom. When they 
were pressed t.i .ad.ipt reinf.irced cmcrete chimneys, because of their absolute lightness, it must 
not b.' forgctten they might have to be loaded up with sand to bring the weight back again. 
MR. E. R. MATTHEWS. 
Thi Lecturer's Replies. — Mr. Dunn made some interesting remarks with regard to reinforced 
c.mcrete chimiu-v-;. ,ind said that limestone concrete sh.iuld never be used in chimney c.instrncti.nn 



THE CONCRETE INSTITUTE. [CDNCBETEJ 

Mr. Matthews did not think he had named that in his paper, but it was certainly a point that should 
be taken note of. and with which he fully agreed. Mr. Dunn considered that lo per cent of water 
in concrete that was to be used in a reinforced concrete chimney was an amoimt to which one should 
not limit oneself, but that a wetter mixture might be used. He did not at all agree with Mr. Dunn 
in this. One or two speakers to-night had agreed with the statement contained in his paper that 
10 per cent, was as much water as should be added to concrete where that concrete was to be subjected 
to heat. 

He was very pleased with Mr. Taylor's interesting remarks, especially his calculations with regard 
CO the strength ot reinforced concrete chimneys. With regard to the methods of calculating the 
strength of such chimneys, Mr. Taylor said that the 28 days' test of his (Mr, Matthews') blocks 
was not sufficient • that a longer test would have been very much more satisfactory. That, of 
course, would apply equally with regard to all tests. The longer period one's tests co\'ered, the 
greater reliance might be attached to the result arrived at ; but, in his opinion, when blocks had 
been subjected to a temperature of 1,250° for 28 days, surely if they were going to crack at all, 
thev would do so in that time. Of the three blocks he took out of the flue, two showed no sign 
whatever of cracking, and they were absolutely white hot ; they were white with heat for 28 days, 
and during that time no sign of cracking occurred or damage in any way, and, in his opinion, if they 
had been in the flue for double that time, they would have given the same result. With regard to 
the consistency of the concrete, Mr. Taylor preferred to use a wetter concrete than that which he 
(the lecturer; had named, and he also objected to the T bars. He also objected to them and 
thought that round bars were far more satisfactory for chimney construction than the T bars. 

Mr Lyle and Mr. Johnson both referred to shafts of reinforced concrete that had been erected 
in connection with the works of Messrs. Abraham Lvle & Sons, and he was certainly very interested 
and somewhat startled to hear that cracks had occurred on the inside of one of these shafts, and 
no sign of a crack — at any rate, the cracks were not nearly so bad — on the outside of the shaft. 
This was contrary to what one would have expected, as in the American shafts which had failed 
cracks had occurred on the outside ; at anv rate, this was so with the one that he particularly 
referred to iit his paper. The surest sign of cracking occurred on the outside, and when an inspec- 
tion was made of the inside of that particular shaft the cracks were certainly visible, but they v/ere 
not nearly so glaring as they were on the outside of the shaft, and he was rather surprised to find 
that the contrary had been Mr. Johnson's experience. He was glad to hear of this experience, and 
it would add considerably to their knowledge of the behaviour of reinforced concrete chimneys 
Mr. Johnson said that if he were building a shaft again he would allow for a 12-in. air space. Well, 
to do that would mean considerably increasing the cost of his chimney ; he would have to have 
a shaft very much larger. 

In reply to Mr. Brown, the blocks he had referred to in the paper were heated on all six sides. 
Professor Woolston, in the experiments that he had been carrying out in order to ascertain the effect 
of heat on concrete, says, referring to concrete heated on one side only: " It shows that under that 
condition the concrete retains a large part of its strength," a nmch greater part of its strength 
Professor Woolston adds, than it does when heated on several sides. He says it can even be 
exposed to a temperature of 1,500^ Fahr. for some hours without any detrimental effect. 

With regard to the thickness of the chimney, he also thought it should be kept as small as 
possible ; the thinner the wall the less tendencv the concrete had to crack. That was, in his opinion _ 
one of the reasons why the Americans built their chimneys with walls so extremely thin. With 
regard to the air inlets, Mr. Faber recommended air inlets through the outer shell into the cavity 
inside. He did not agree with Mr. Faber there, for the reason that Mr. F.tchells had already given, 
that the mechanical engineer would certainly say this was considerably interfering with his work. 

Mr. Etchells told them that the London County Council Regulations required a shaft 300 ft. in 
height to be 6 ft. in thickness at the base, so that he was well within bounds when he said 4 ft. 10 in. 
Mr. Etchells said also that the base of a reinforced concrete chimney, if it was in bad groimd, 
should be considerably spread. It was so in most of the designs shown : the foundations extend 
to a considerable width, in some cases 36 ft. and 38 ft. square. The nature of the aggregate in the 
EngUsh chimneys was asked. He thought, but was not quite sure, it was Thames ballast. He 
fancied that Thames ballast was the aggregate used in the chimneys of Messrs. Lyle and those at 
Northfleet. 

Mr. Lyle: It was all washed Thames sand, clean Thames sand, 3i to i. with no stone whatever. 
If you put stones in they would fly and split the concrete. 

The Chairman : They were much obliged to Mr. Matthews -or his \'aluable paper, and wished to 
pass him a cordial vole of thanks. (Applause. I 
The meeting then teyminaled. 



Iz6 



f J. lON.MlJDiriONAl.l 



REINFORCED CONCRETE SILOS. 



NEW WORKS IN CONCRETE 

AT HOME AND ABROAD. 

Unaer this he^J/ng reliable tnformjttton 'will be preseuteJ of new •works in course of 
construction or completed, jnd ttte examples selected •will be from all parts of ttie 'world. 
It is not the intention to describe these VJorks in detail, but rather to indicate their existence 
and illustrate their primary features, at the most explaining the idea which served as a basis 
for the design.- ED. 



REINFORCED CONCRETE SILOS AT HULL. 

I'lic ^lain silos dcscriht-d in tliis .irliclc wt-rc put up fi>r Messrs. Josepli RaiiU, Ltd., 
.11 Hull by Siu.-irt's (Ir.iiiolilhic C(i., Ltd., ol 4 Konchurcli Strt'ct, London, E.G. 

The buiklinj.^: is one of the largest of the kind constructed of reinforced concrete in 
this country, the size and importance beinsj clearly seen from the accompanyinjj 
illustrations. 

The total outside dinu-iisions of the buildini; are St) ft. 3 in. by -9 ft. 9 in., the 
lieifiht being 90 ft. from hoppi-r beam level. 

There are 81 bins, each go ft. high, also 12 screen bins 46 ft. high, and 7 rope race 
bins 30 ft. high. The other dimensions and arrangement will be seen on drawing on 
p.-,ge',2l.. 

.\ll the division.il w.ills .are 4.\ to 5 in. thick. 

The .ipproxim.ile capacity for strain in these silos alone is 1 1,000 tons, the 




Reinforced Concrete Silos at Hu 



\7-y 



XEW WORKS IN CONCRETE. 



ICDTCBETFJ 





1^ 


jii 




~ - - 


■ij 




■ ■■ 1 


4 1 


-.-i ! 


"tL 






;"( ? 







H^^k^^. 




128 



I J. LONjrrEUCTKJNAIJ 



RHIXFORCED COSCUHTB SILOS. 




129 



.V£W «-OJ?aS 1-V CJ-VC«£T£- 



jc5v: 



IC "SS i"»Jj 







Tte aoniffiTS -SOS mc in- ic rsjac* 3ii& CTt _. 



= are i& 3e ciiUt-Jdj- 






:5r 



f J. iXMSrUlK-llONAlJ 



REISFORCED COSCRETE SLIPWA V. 



in llu lUtt lilclmat sli|>w;iy, ri-ci-ntly coiislructi-d for ihi; Kuyal National Lifeboat 
liistitutlun, at tlit'ir Acker.nill Station, near Wick, in the north of Scotland. 

I ntil recently lifebo.it slipways have been constructed of steel rolled sections or 
limber, but, rec«ij,'nisin{J the advantai^es of reinforced concrete with rej^ard to main- 
tenance anil durability, it was decided to construct the new slipway in this material, 
and our illu>lrations show the work durinjj erection and upon completion. 

The slipway has a total lensjth of 194 ft., the seaward toe being formed of mass 
concrete, and the remainder of reinforced concrete, supported on columns spaced about 
JO ft. apiirt. .\t the u|>|)er end. for a Ienj;th of 58 ft., and carried on three rows of 
coUimns, there is a platfi>rm 5 in. thick and if> ft. wide, which forms the berth for the 
lifebiKil and hauling winch, the height above the shore end being about 16 ft. .\ drop 
keel of o|)en decking is provided under boat platform at a height of about 10 ft. above 
shore level. The remaining portion of the slipway is laid with a gradient of i in 7 
down to low-water level, and is constructed of open framework on two rows of 
columns, thus olTering as little resistance as possible to the heavy seas encountered 
on this OMst. It consists of longitudinal keelvvay beams in pairs, 20 in. deep by 12 in. 
wide, between which, at intervals, are rollers supporting the lifeboat keel. There are 
lU.. 1.111 i^itudinal bitgeways and cross beams 11 in. deep by 8 in. wide, sp-!'--' :• " "^ in. 




B^ncfrcac£J2 Cascasrnm £_cffXBi3>&r ^jpvat ax AckesdvILZ- 

ai{!S!tn: for tbe emcire Ceeig:^ of sGipvay, tbe vboie surface being' designed to resisc the 

heavT sAkk&s wiindi imay be eacvocEranered by auav cttember frocn cbe impact of tbe life- 
Btioaii mi TOtigfei sea& 

Chu OBte siiJe- 10*' &ss slipwav sBisene- is a pnojectirag stepped platfonn 4! in- thick, 
wicft :c^-<:— r(f surface E* pjravKie foeci^jM, and carried 00 caneil^«r bcackets from the 

ftjLC'.: ■ -'i^linTrC 

^ stsppiDciamg^ the s&xaesmis ant of ocEagooal sectioa 14 in. in diameter, 
wi: ■ -. - . . Si im. siju..ir>r cikeni dujiirm 2 ft. mxxt Ehie soEd rack, of wWcfa tiie fore- 
sfiwctt its cw^iiifjiosed, - '. ajicfoiocaige- wiis secimred bj carrying' doiTi the 

verlincaJi bcEirs ^ t&<s- rr : ji a t fi iT rfw^ (jfepcfo ii>f e^ iis- ioBiy hotes fciDced bei the 

BUHdk atiad afceraraanfis s^r-^.; ; .. .ii meat cfflmeEiir. 

Tbe iniif tnrmmTig aumi aiTu feiiTTwrrmij^ wieire r^imfioceed with sceel spiraMiinig' \n additicjfi tsy 
ttoegSiMi&iaJ! fears, ansi MB aefrraiicatse was EaketE of cauriHioiEy im (tearnMBiiig the 
sectfom uf beamirs aimii gSniersL 

131 



NEW WORKS IN CONCRETE. [CONCBETE] 

The reinforc.^d concrete details were i.reparc^.l by the Considere Construction Ca., 
Ltd., of 5 Victoria Street. S.W., from tlie desij-ns of Mr. W . 1 . OouKdass, M.lnsi.t .K.. 
View sfiowirg arranscment of Temrorary ShullerinR to 3 spans. 







span5 of Reinforced Cone 
LBOxr Slipway at Ackef 



.TIONAll 



RHIXFORCED CONCRHTH FLOORING. 

Ill [^ \itli.ii.i Sli<i-l, WVslininslir, lCn);ijniT Id tlif k(i\,(l Na.idiial l.ik'boMl 
Inscitiitiun. 

The fxiculinn of llu' work i-ntaiU-d considorablc ililTiculty ;intl c.illetl fur exlremc 
cart', o\vin)4 lo the lic.ivy ^cas cncountiTwl during; conslructitin, and was satisfactorily 
carried out by Mr. K. K. Lester, of Plymouth, licensed contractor for the ("onsidir'' 
System. 

A similar sli]i\v.iv on the same svslem is at present in course of construction at 
M..rlln-, .\ni;lesey. 

FLOURING AT THE EXTENSION TO SHEFFIELD ROYAL INFIRMARY. 

Tim-: ilhislr.ilinns \vc procnt --how ilu' new rxlmsion lo SlKilicld l\o\;d Infirmary, 
where the lloors ihroii^'hont .ire Im iiii; l.iid liv ihe ArinoiM'ed Tuboiar l''loorin,L,' Co. upon 
iheir patented s\slem, to tlie specification ol Messrs. (iibbs \- l-'IocUton, architects. 

These views show the m.-i^jnitude of llie buildinj;, which contains over ^.ckk) sq. yds. 
of Armoured Tubular lloorintj, more than one-half of this area beinjj of clear sjjan of 
ji) ft. in \vards and Hat roofs over same, these spans neccssitatinsi reinforced concrete 
joists of the unusual lentjth of 28 ft. 




Tlie joists and all units were manufactured on site by temporary plant and 
machines, in .iccord.ince with this patented system, and are sftown in Fig. t in 
transit from works to buildinj,', and in h'ig. 3 as they apix^ar when laid with spacini;- 
concrete tubes before the application of the lop layer of concrete. 

The nominal worUintr '"-''d upon 26 ft. span ward lloors may be taken at A cwt. 
per sq. ft. F;>. 3 shows test upon sample span of 3 joists loaded in accordance with 
arcllilect's r-i'i|uii . imni - i.. ; ewi. \n-\ ^i|. f ' . , uiiich -a\c a mininuini of ' th span 




detlection with entire absence of fracture in concrete, whilst completed floors tested to 
;.; times their workini; load sjave deflections of j„V,t part of span, this disappearing 
entirely on the remov.al of load. 

The many adv<intages of this system, and more particularly the unbroken soffit 

■'33 



NEW WORKS IN CONCRETE. 



[CONCRETE] 



possible on wide spans, nialce it specially serviceable for hospitals and schools, and 
in buildings of the latter type, spans of 26 ft. 6 in. are being completed in Birmingham, 
whilst on the Continent sp,-ms of 30 ft. have been constructed with entire success. 

NEW BOTTLING STORE IN REINFORCED CONCRETE 
FOR THE DARTFORD BREWERY. 

Reinforced concrete has lately been very extensively applied to brewery work, and 
the accompanying illustrations of the new bottling store which has recently been 
completed for the Oartford Brewery, on the Coignet system of reinforced concrete, 
show another application of this method of construction. 

The architect for the worl< was Mr. .-\. J. Style, F.R.I.B..\., and the contract was 
carried out b\' Messrs. William F. Blay, Ltd., of Dartford, licensees of the Coignet 
system. 

The building is compo'^cil of a ground lloor ur ct-llar to receive casks. The first 




New BOTILINU SluRE FUR I HE L*AKltuKD liREWtKi. 

floor is used as a bottling store and is fitted with machinery, as shown in the 
illustration on this page. 

The building is covered by a flat rt><_>f containing four openings with lantern 
lights. 

The general dimensions of the building are approximately 75 ft. by 45 ft., and the 
height, measured from the floor of the cellar to the top of the roof, is approximately 
19 ft. 

.\ noticeable feature ot this bottling store is that the walls are also made in 
reinforced concrete 4 in. thick. 

.\ cantilevered loading platform has been provided for, and this is illustrated on 
page 137. 

The principal reason for the adoption of reinforced concrete for this work was the 
question of economy and durability. 

•34 



I J, lON> 1 l.'(ll I IONA1.1 
L'V l.N(,lNl.l.lJINti —J 



BOTT/JNC fiTORf-: AT DARTFORl). 




NEW WORKS IN CONCRETE 



ICONCBETE i 



J 



r] 



I 



. - I IP J_ 

^ - 7 .7 "0 

J ! 4^ I I 




136 



^ 



.l&NMPDCTIONAl] 
N(ilNt.l.BIN<. ~J 



BOTTLING STORE AT DARTFORD. 



I Iw li aiiis iliDu^hniil llic liuildiiij,' were made accordiiifj; lo the ("oij^rifl systc-jii 
u( '■ equal nsi>lancc licams. " Accortliiif^^ lo this method the tension bars, generally 
seven in nirnlHT, arc j^raduallv bent up at aji antrle of 45° and hooked over a lon;;i- 




tudinal inii liar. In this manner the lient portions are made to resist the shearinj^ 
elTorts, and these shear members are spaced closer towards the points of support. 

On pafi'e 136 we show plans and sections of the buildintj, and on page 135 we gfive 
some details of the work. 



NEW USES FOR CONCRETE. 



ICQNCCETEl 



NEW USES FOR CONCRETE 

AT HOME AND ABROAD. 

Under fhis beading reliable information ivtll te presented as to neiu uses to luhich concrete 
jnd reinforced concrete are put, ivith data as to experience obtained during the experimental 
stage of such neiv applications of these materials. The use of reinforced concrete as a 
substitute for timber in exposed positions is one of the questions of the moment. Railtuay 
sleepers* telegraph posts, fence posts, etc., of concrete are being tried. Similarly, efforts 
are at present being made to prove that reinforced concrete is an excellent substitute for 
bricktuorkf *u)here structures of great height are required.— ED. 



A REINFORCED CONCRETE CONDUIT AT WOOLWICH. 

TiiR accompanying^ illusiralions slmw a reinlnrced concrete conduii that has been 
recently constructed at Woolwich, and which is ihe first conduit in l.ondon district to 




Q^ 



C10N»TPI)l"naNAl.l 
EN<ilNt:F-HlNCi~-J 



RHINFORCHD CONCRETE CONDUIT. 



!)<■ cdiislructcil nil wliicli the- 1 
I'ifi- 2 sliows the section of 




111 Ihe 



.•uiy^le iron i> placed 

l):il!s I J in. diameter. Tlie 

of the concrete was particidarly smooth 



aw s\>Ieni of eollapsihlc-^leel centerinj^ lias l)een used, 
same, whilst /•/.i,'.\'. i and 3 j.jive illustrations of the 
centerinj^ in use. 

The centres were half 
round and 2 ft. 6 in. dia- 
meter. The o|>eration for con- 
structinfj; the invert was to set 
up the centres on a dish of 
concrete, and then concrete 
up to the sprinf^infj line. .Xs 
soon as this was set the 
centres were reversed and set 
up on timbers for concreting' 
the crown. 

.About 20 ft. of centering 
was concreted at a time, and 
as soon as it was set the 
centres were collapsed and 
pulled forward on Ihe angle 
"I CoMH IT. irons, as shown in the illus- 

tration. .V corresponding 
ntri-, and ihe rolling forw.ard is carried out by means of 
were found to pull forward very freely, and the surface 




Reinforced Concrete Conduit at \Vc 



139 



NEW USES FOR CONCRETE. 



[CONCBETEl 



An 

contract 

We 



tlie 
the 



inlere--iinL; feature is the low cos( of Ihe centerinjj; whicli \\,is leased fo 
, the cost of centering per foot of conduit only amounting" to about lid. 
may remark here that this centering- is beintf used exclusivel\ or 
' Collector for the Cairo Drainaj^e Scheme, and on many other im- 
portant works in 
this c()unir\ anil 
al.n.ad. 



V REINFORCED 

CO NCR ETE 

FOUNTAIN. 




Tile lountain 
at Caergwrle Spa, 
North Wales, of 
which we show an 
illustration, is an- 
other example of 
the use of rein- 
forced concrete for 
ornamental pur- 

This fountain 
is about 15 ft. in 
diameter, the 
walls and bed 
being- made in situ 
of reinforced con- 
crete, in which ex- 
panded metal was 
Lised. 

The central 
pillar supjxirts a 
concrete basin, 
which carries the 
brass fountain. 

The basin is 
surrounded by a 
balustrade. The 
bass, capping, and 
balustrades were 
made in Liver- 
pool, and were 
carted to the site. 

This fountain 
was erected bv 
-Mr. John S. Rigbv, 
F.C.S., of ' 26 
Bagot Street, 
Liverpool, and has 
given entire satis- 
taction. 



HOW TO MAKE CONCRETE POTTERY. 



Few people realise that anything of an artistic nature can be made from Portland 
cement, says a writer in the Manchester Weekly Times, wlu) has followed the Portland 
cen-ient industry for a great many years. Most of us are used to looking on this 
material as fit only for heavy construction work, such as foundations for buildings, 
bridge abutments, piers, &c. It is not remarkable, then, that the lavman does not 
know that cement, if properly used, can be made to compare more tha.i favourably with 
ornaments made from other and much more expensive materials. 



'+° 



m 



5aC] 



CONCRETE GARDEN BENCH. 

I'.iril.Hul onu-nl nu.rlar, of whicli ceincnl |..,(i,tv is iii.ulc, is o.inM„s,-,| of •. 
nux.urc ul sa,u or marbl. dust and pure Portland ccMnent ntix.d . o^.h" ' ar xi^s 

proportions. 1 Ins m.x.uro rs wet down with wat.T. and then, In UrilVove and 
trowel Mig, ,s n>ade nito a plastic n.ass calkKl cenu-n. n.or.ar. I i; n x , in p ossil 
to model in this material, for the nnpossiDU 

reason that unless it is placed in 
a mould, or a form is used tcj 
hold it in sh.i|X' while in its 
plastic slate, it will fall down. 
The first step then in eeineiu 
ix)ttery work is to m.ike the 
lorm, either by makint,'- wire 
frames on which to huild tip the 
cement mortar, or by makini; 
WDoden or plaster moiikls. 

The use of wire forms, ;is Wire Fomnsi'oKMAKiNr, Concrete Potterv. 

ilkistrate<i, is the simpler when there are but one or two of the same shape of articles 
to be niade. When a cjuanlity of one kind is to Ik.- made it pays well to spend some 
time in makini? a wooden or plaster piece mould, as it can be used over and over af,'ain, 
whereas when wire forms are used .1 new form has to be made for each article, 
whether of Ihe same shaix' or not. 

CONCRETE GARDEN BENCH. 

I whieli ur i;ive an illu-.tratiun is very simple in outline 
n .■iiiraiii\e ex.imple of ihe utility of concrete for garden 




MI96 



The sj;^ardeii bench 
and treatment, and is 
work of (his character. 

The bench is 12 ft. Ion- .uid .s H. wide, and, as will be seen in the photograph, 
the concrete has ,1 rou^h surface except on Ihe seat, on which the face is smooth. 




The concrete is composed of Portland cement, coarse, sharp sand, containing some 
gravel, and cinders, mixed in the proportion of i, 2i, and 5. The flooring is made 
of tiles, and tiles are also carried in a band along the back of the seat. The tiles 
are in artistic shades of red and blue-green, and are especially appropriate and pleasing 
when combined with this class of concrete work. 

We are indebted to our contemporary. The Coiioit Age, for the illustration. 



M' 



NEW BOOKS. 



lOQNCRETEl 



NEW BOOKS 

AT HOME AND ABROAD. 

A short summary of some of the leading books vihich have appeared during the past year, 



Chemistry for Builders. The Chemistry 
and Physics of Building Materials. By 
Alan E Munby. 

Published by Constable .V Co . Loii<ion, lyoy. Six 
Sliilliniis net. 

Contents. — Natural Laws and Scienlific 
Investijjalions. — Mc-asurements and 
the I'ropt-rtics of Matter. — The Air 
and Combustion. — Heat : its Nature 
and Measurement. — Heat and its 
effects on .Materials. — Chemical 
Signs and Calculators. — Water 
and its Impurities. — Sulphur and 
the Nature of .Acids and Bases. 
—Coal and its Products.— Outlines 
oT Geology. — The Constituents of 
Stones, Clays, and Cementing 
Materials. — Classification of 
Stones. — The Examination and 
Testing of Stones. — Brick and 
Other Clavs.— Clays [continued). 
Kiln Reactions, and the Properties 
of Burnt Clays.— Plasters and 
Limes.— Cements.— Theories upon 
the Setting of Plasters and Hydrau- 
lic Materials.— Artificial Stone : 
Oxvchloride Cement ; Asphalte.— 
The Metals : their General Proper- 
ties and Occurrence.— Iron and Steel. 
-Other Metals and .Alloys.— Tests 
upon and Strength of the Metals.— 
Timber.— Paints : their Solid Ingre- 
dients, Bases, Pigments, and Driers. 
The intention of this book is to instruct 
persons interested in the use of building 
materials but having no scientific know- 
ledge in the chemical and physical 
properties of those materials. With this 
object, the first part of the book is de- 
voted to an outline of the sciences^ in 
question, and the second to their applica- 
tion. It may well be questioned whether 
such a plan i's the best to be adopted. To 
write an elementary treatise on chemistry, 
phvsics, and geology in the space of 104 
pages of rather large type is an enterprise 
foredoomed to failure, the information 
given being necessarily very superficial, 
and it may be doubted whether an engineer 
or builder, unaccustomed to the use of 
chemical equations, could derive any benefit 
from so brief an outline as is here given. 
We are glad to be able to speak in much 
more favourable terms of the second part 
of the book. Building materials are dealt 

'42 



with in the order named : stones, plasters, 
limes and cements, metals, timber, and 
paints. The information as to the nature 
and properties of each material is con- 
cisely given, and wc have noted very few 
minor inaccuracies. The section dealing 
with Portland and other cements is par- 
ticularly interesting, and includes a clear 
statement of some of the rival modern 
views of the nature of the setting process. 
Some references to the changes which 
cement undergoes during storage would 
have added to the usefulness of this 
section. It is highly desirable that users 
of cement should have some idea of the 
chemical character of the material with 
which they have to deal, and the present 
work may be recommended for this pur- 
pose. The chapters dealing with paints 
also contain much that is of interest. 

We would venture to suggest that the 
book would have been improved by the 
omission of Part I. altogether, referring 
the reader to other easily accessible sources 
of information, the space thus saved being 
utilised for a fuller presentation of some 
points which it has been necessary to treat 
rather hurriedly. 

Much useful information has been 
brought together in a small compass in 
the second part of the work that should 
prove helpful to many persons engaged in 
ci>nstructional work, and for that part 
alone the volume may be commended. 

CoaKt Erosion and Foreshore Protection. 
By John S. Owens and Gerald O. Case, 
M.D., M.Inst.C.E., F.R.G.S. 

Publi^ied bv I he St, Bri<ies Pre=^. Ltd., London, 190S, 
Seven Shillings .nid SiM" iic- net. 

This is a most useful booklet, and has 
appeared at a most appropriate moment, 
when serious consideration is being given 
to the protection of our coasts from en- 
croachment by the sea. 

The facts are concisely presented; the 
tvpe is good, and even if the advocacy of 
reinforced concrete is somewhat ex parte, 
having regard to the well-known views of 
the authors, the book certainly should 
have its place in the library of every local 
luthoritv having to deal with foreshore 
questions. 
Tables for Reinforced Concrete Worh. 

Messrs. Julius Springer, Berlin, have 
]:iuMislu'd at the price of marks 0.60 (about 



r j.i'oN.iWH-noNAi.i 
tft-t-M(ii.Ntii<i^«. —J 



(k1.). a li.imly folding' sliet-t, omipikd 
by Engineer (i. KunUe, l-eipziji, entitled 
" Tabellen fiir die Berechniing von 
EisenbetonUonstruktionen," and giving 
factors and coelVicienls for calculating 
reinforced concrete worU. The figures in 
the tables are in accordance with the 
Ministerial conditions of May 24th, 1007, 
and with those of the German " Beton- 



The Theory and Design of Structures: ,\ 

Textbook for llu j-.'i.' "' SIli.Uills. ;)r■,l.<f.•'l^•^"l.■<l 
aiul Ftii;iia-iT.s.'/i..n:i-.' l" <:c>llslri,cllon„l Work. 

By Ewart S. Andrews, B.Sc. Eng. 1 Lond.), 

;.<;c«iirfr <i( the Goltlsmilh ColUile. .Vtw Cross. 
Published by Chapman & Hall. Ltd., London. 1909. 

Nine ShillinBs. 
Conlents: Stress, Strain and Elasticity.— 
Principles of Design; Working Stresses, 
etc. ; Wind Pressure. — Vorccs, Areas and 
Moments.— Riveted Joints an<l Connec- 
tions. — Hending Moments and Shearing 
Forces in Beams.— Stresses in Beams.- 
Bending Moments and Shearing Forces 
for Rolling Loads.— Dcllertions of 
Beams. — Fi.vcd and Continuous Beams. — 
Distribution of Shearing Stresses in 
Beams. — Framed Structures. — Columns, 
Stanchions and Struts. — Suspension 
Bridges and Arches. — Masonry Struc- 
tures. — Reinforced Concrete and .Similar 
Structures. — Design of Steelwork for 
Buildings, etc. — Design of Roofs. — 
Design of Bridges and Girders. — lC.\er- 
cises. — Tables of Properties of British 
Standard Sections.- 
In the preface the author states half apolo- 
getically his object in " Adding to the list — 
already long — of textbooks dealing with engi- 
neering science." Certainly the subject of 
the Theory of Structures has received rather 
more than its due amount of literature; the 
reason no doubt being that each lecturer on 
the subject has his own ideas as to the best 
method of imparting such knowledge to his 
students and the proper sequence in which it 
should be presented to them. The latter con- 
sideration is a very important one — like the 
chef's duty in preparing a menu — in order 
that the student's brain may properly assimi- 
late its mental food. 

In the case of this textbook the author may 
certainly be excused " for adding to the list." 
He has achieved his object in providing at a 
reasonable cost a clearly written te.xtbook, 
covering almost too sufficiently wide a 
ground, avoiding all unnecessary aid of the 
calculus and higher mathematics where the 
demonstration may be made by simpler 
means. Another feature of the book is that 
the graphical and analytical methods of deal- 
ing with bending moments and stresses are 
made to go hand in hand; this is quite as it 



NEW BOOKS. 

should be. Too often the two methods are 
kept severely apart, so that instead of one 
being taught as com|dementary to the other, 
they, and more especially the graphical 
method, lose much of their coherence when 
their partnership is dissolved. .-Vs the engi 
necr gains in experience he will probably 
learn to rely less and less on the graphical 
method, as the other is of greater accuracy 
anil the results can be obtained far more 
rapidly. At the same time, the graphical 
system enables him to form, as it were, a 
mental vision of the mathematical calcula- 
tions. Occasions may also arise where the 
engineer in his practice is called upon to de- 
sign some structure outside the ordinary 
course ; in that case the graphical method is 
of great assistance as a guide and a check 
upon his calculations. 

The sequence in which the author deals 
with his subject may be gathered from the 
Chapter headings. That the relationship be- 
tween stresses and strains is a matter of cause 
and elTect is undoubtedly starting the student 
along the right path. I'ntil recently strains 
played a comparatively unimportant part, but 
since the introduction of reinforced concrete 
they have, so to speak, come into more daily 
use, forming as they do the basis from which 
the formula! for composite beams are deriveil. 
In Chapter II. the author rightly condemns 
the " Factor of Safety " heresy in dealing 
with working stresses. Chapters I. to X.. 
also Chapter XII., wlijch might well have 
preceded Chapter XI., would come more ap- 
propriately un<ler such a title as "The 
Strength and Resistance of Materials." 
When the author at Chapter XI. reaches what 
to the majority of students is the most fasci- 
nating portion, viz., " Framed Structures," he 
appears to pass very rapidly along his subject 
at this stage. Chapter XV. deals sufficiently 
ade(iuately, as far as the student is concerned, 
with the theory of reinforced beams and 
columns. If he thoroughly grasps what the 
author calls the " .Straight-line no-tension 
method " the rest should come easily to him. 

It seems almost unfortunate that the .author 
should have included " And Design " in the 
title of his book ; the remainder of his book 
is apparently included to justify this much of 
the title. The various systems of reinforced 
concrete might well be presented to the student 
in the form of a collection of handbooks 
issued by those firms. Design is rather to be 
obtained by actual practice. A few months 
in the drawing office of a constructional steel 
contractor may not give to the young engineer 
much experience in the theory of structures, 
but will more than make up for it in the 
matter of design. The weak part of the book 
is unfortunately what its title implies, viz., 
the theory of structures, especially framed 

1+3 



NEW BOOKS. 



[CQNCKETH 



structures. What miKht more :ippropriatel>' 
come under the heading of " The Strength 
and Resistance of Materials" is the best por- 
tion of the work. Undoubtedly the book 
would be vastly improved by sacrificing the 
" Design " idea and devoting the space to a 
fuller consideration of the framed structure 
pure and simple. The last half of the book 
leaves an impression that the author has far 
more to say than there is ^pnce within which 
to express it. 

Practical Building Construction : A liutid- 

book fur Sllidiuts l^icpiiiini; for the lixti niiucl- 
Hcns of tin- SciL-iicc und Art Depctrtnn-nt. the 
ltO\<ll Ilisiitiiti- of British ArchilLct-.. the 

SkVtcvoi-s' hislitutton. etc. By John Parnell 
Allen, Formerly Lecturer on Buitding Con- 
at the Armstront College of Science. 



Neu 



stlei 



-Ty, 



Published by Crosby. Lockwood & Son. London. 1909. 

Seven Shillings and Sixpence. 
Contents: Bricks and their Composition. — 
Brick Bond and its Applications. — Brick 
Reveals, Arches and Pointing. — Damp 
and its Prevention. — Building Stones and 
Stone Walling. — Stone Dressings, Joints 
and Stairs. — Wood for Building Pur 
poses. — Wood Floors. — Partitions. — 
Roofs. — Iron and Steel. — Rivets and 
Riveting. — Iron Roofs. — Coverings for 
Roofs. — Fireproof Floors, Partitions and 
Ferro-Concrete. — Joints and Mouldings in 
Joinery. — Doors : Their Finishings and 
Fastenings. — Windows and Window 
Finishings. — Wooden Stairs. — Skylights 
and Lanterns. — Plasterings, Painting and 
Glazing. — Centering, Foundations, 

Shoring, Scaffolding, Sewers. — Miscel- 
laneous Materials. — Stresses. — Calculation 
of Strains. — Sanitation. — Fireplaces. — 
Weights, Strengths, Quantities and Prices. 
— Tools Used by Various Trades. 
That Mr. Allen's book has now reached a 
fifth edition evidently testifies to the fact that 
it satisfies a want. The book may be described 
as an abridged encyclopaedia on Building Con- 
struction. So much so that each chapter may 
be said to contain sufficient material on which 
a book equally as large might be written. 
The striking feature of this book is the num- 
ber of illustrations and definitions of technical 
terms it contains. Covering such a vast field, 
perhaps it would be advisable to confine this 
review to that part which deals with rein- 
forced concrete and constructional steelwork. 
Chapter XV. devotes three pages to " Ferro- 
concrete," containing a short description of 
what it is, " Materials," " Tests for Cements," 
" Aggregate," " Mixing," and " Construc- 
tion," followed by some illustrations of 
various^ systems. 

As regards constructional steelwork. 
Chapter XXIV. is devoted to "Stresses." 
Some of the definitions here given are de- 

■++ 



cidedl\' peculiar — t\g., ''T/ir bending momeyt 
indicates the extreme weight, or maximum 
stress, applied to a member to make it col- 
lapse," while the moment of resistance denotes 
the opposite — i.e., " the strength of a member 
short of collapse." 

Apart from the fact that a bending 
moment denotes any variable amount, it is 
neither a weight nor a stress. So, too, in the 
following chapter, " Calculation of Strains," 
the word "Strains" is employed in an 
erroneous sense ; in strict engineering parlance 
there is no such thing as "A twelve tons 
strain." As the book is intended for students 
these two chapters might with advantage have 
formed part of the revision of this new 
edition. 

It were better for the student, if he intends 
to make a further study of this branch, to 
approach it with an open mind, rather than 
have to unlearn its elementary principles. For 
this reason especial care should be taken in 
such a book as this, written, as it is, in order 
to " lead many students to seek a more com- 
plete mastery of the particular subjects to 
which they may find it best to give special 
attention." With the above reservation, it 
may be said that the book should offer, 
especially as regards the copiousness of the 
illustrations, a sufficient incentive to achieve 
this object. 

A Concise Treatise on Reinforced Concrete. 

.4 Comfy, in, o„ to ''Tli- Remfi-rced Concrete 
M.innal- By Chas. F. Marsh. M.Inst.C.E., 
M.Am.Soc.E., M.Inst.M.E. 



Contents: Properties. — Behaviour under Load- 
ing. — Xecessary Assumptions for Purposes 
of Calculation. — Methods of Calculation. 
— Methods of Reinforcement. 
Two of the best known and best received 
books on the subject of reinforced concrete 
which have been published in the English lan- 
guage are "Reinforced Concrete" and the 
"Manual of Reinforced Concrete," of which 
Mr. Chas. F. Marsh and Mr. William Dunn, 
F.R.I.B.A., are the joint authors. Mr. Marsh 
has now written a companion volume to the 
manual, which has just been published. The 
large treatise deals more fully with every 
aspect of the subject than does this work, 
but the reason expressed in the preface 
for its publication is that the publicity 
given to the use of the material since 
the first issue of the larger work has made it 
possible to treat the subject in a considerably 
more condensed manner than was justified a 
few years ago, since details of construction 
and lengthy descriptions of experiments no 
longer possess the special interest they had 
in the immediate past. This book should in 
part meet the demand which there is for a 



\K 



t;N(ilNtJEJ<IN(i —I 



A'/?U' HOOKS. 



1 OIK isf anil li.iiicl} volume, aii<l certainly the 
author has manageil to deal very dearly anil 
very tomprehensively with a subject wliieh it 
is rather iliffieult to express shortly. This work 
ileals mostly with theory, with some short 
references to experimental ilala, and a con- 
eluding chapter on some methods of rein- 
fori ing various structural members. There 
are points in theory upon which most 
specialists in this form of construction dilTer, 
but Mr. Marsh has very clearly slated the 
reasoning upon which his conclusions are 
based and the limiting factors of the problem, 
though we arc inclined to think that some of 
the factors which he dismisses as of minor 
importance deserve more consideration and do 
alfect the design considerably. As an intro- 
ductory work, however, the book is most 
l)iaiscworthy. .-Xny student thoroughly digest- 
ing this work will be led to investigate the 
subject further. We think that a warning 
needs to be uttered in view of the increasing 
number of text-books on the subject in respect 
to the im|)ortance of reinforced concrete work 
being designed b\' those who have specia!ise<! 
in the subject. The time is not yet ripe for the 
general practitioner to attempt to deal with the 
subject : even specialists find many awkward 
problems, ancj know the advantages of experi- 
ence, and if they find a subjec:t sometimes 
intricate and needfcil of great care to avoid 
grave errors, entailing perhaps danger to life, 
it proves that it woidd be clangerous for archi- 
tec ts and engineers generally to undertake to 
design such work without specialising, to say 
nothing of the loss that. may be occasioned and 
extravagant employment of materials. 

We hope that this first edition will meet 
with a ready sale, and that in succeeding 
eclitions the standard notation of the Concrete 
In-lil.ilc will !.<■ adopted. 

The Theory of Structures. By R. J. Woods, 

M.E..,M.lnst.C.E..,l\llotc timlfornurly^ssis 
ttint I rofessor n.l Eimiticeriiti!. ffojvi/ Indian 
Bnninecring Cotlenc Cooper's Hilt. 
Published liy Edward Arnold. London. 1909. Ten 
Sliillinus and Sixpence net. 

Contents: Compound Stresses. — Principal 
Stresses. — Earth Pressure. — Stresses due 
to Eccentric Loads. — Working Stresses 
and Cross Sectional Areas. — Stresses in 
Girders with Parallel Chords by Method 
of Co-efficients. — Girders with Parallel 
Chords.— General Method.— Parabolic 

Girders. — Curved Girders not Parabolic. 
— Wind Pressure. — Portal Bracing. — High 
Steel Trestles. — Continuous Girders. — 
Cantilever Girders. — Suspension and 
StifTening Girders. — Design of Riveted 
Joints. — Plate Girders. — t/olumns and 
Struts. — Arched Ribs and Braced Arches. 
— Reinforced Concrete. 
This volume, although perfectly complete in 

itself, is a continuation of the author's 



|)revious work, entitled ■ The Strength and 
Elasticity of Structural Members." 

A large portion of the book is devoted to 
the working out of |)raclical examples, which 
makes it particularly useful to students, and 
.dso as a reference book for engineers and 
architects. 

The last chapter only is devoted to rein 
forced cone rele, and we regret that the author 
did not devote more s|)ac e to this important 
subject. This c hai)ter gives the advantages 
of reinforced concrete, and also an idea of 
the many clilTerent kinds of modern buildings 
in which it can be used with success. It deals 
at length with the crushing strength and the 
safe compression of concrete in beams and 
columns, and with (be adhesion of concrete to 
sti^el and the shearing force in the we! ^ ;1 
reinforced concrete beams. The working 
stresses in reinforced concrete are dealt with 
very explicitly, and examples are given of the 
methods of calculating the many forms of 
reinforced concrete with the various formul.-i- 

Concrete Steel Construction. Part I 

Buildings. -I I'riulmil r realise lor the Cons'.niclor 
and Ihote emnmerciallv enlaced in the imlustry. By 
C. A. P. Turner, M.Am.Soc.C.E. 

Published l.ylh.: Farnhaiu I'linciiig \- I'ublohinf Co.. 
Minneapolis. Twenty Dollars. 

Contents: Materials.— General Types of Con- 
crete Steel Construction. — Computation. — 
Tests of Slabs and Floors. — Discussion of 
Theories and Elastic Properties. — 
Columns. — General^ Principles Governing 
luonomic Design.'— Systems of Rein- 
forced Concrete. — Foundations. — Working 
at Various Temperatures. — Bending Steel. 
— Protection of Steel and Provision for 
Plumbing and Plastering.— Fire Protec- 
tion. — Floor Finish. — Responsibility of 
the Engineer and Contractor.- Rapidity 
of Construction. — Centering. — Cost of 
Work. — Permanence of Concrete Con- 
struction. — Reciuirements of Different 
Classes of Buildings. — .\rtistic and Com- 
mercially Practical Concrete Surface 
Finishes. — Casualties and Accidents. 
.Af-pendix: Siiggestions for a Concrete Con- 
structor's Library. — Shipment of Cement. 
— Patents and Patent Laws. 
This book is written from the contracting 
engineer's point of view, and consequentlv 
differs very materially from the usual treatise 
on reinforced concrete. Practical considera- 
tions in construction arc given the preference 
over theoretical formula-. The writer evi- 
dently prides himself on what he as an Ameri- 
can would probably term his " good horse 
sense " ; and it may be said that his book con- 
tains an ample amount of this commodity. 
As against this must be place a detracting 
feature, viz., that the book is written mainly 
with a view to extolling the author's own 



NEW BOOKS. 



[CQNCBETE] 



patented method of construction; in fact, it 
may be termed a glorified catalogue of the 
" Mushroom " system of reinforced concrete 
floors. No doubt this system is in every way 
an excellent one ; in fact, so much so in the 
author's opinion that the other methods re- 
ceive at his hands but a scant amount of 
courtesy. Briefly put, the author ilivides floor 
construction into four types, viz. : (i) main 
beams between columns carrying intermediate 
bearer beams with slabs of short span ; (2) 
main beams in one direction only with long 
span slabs ; (3) main beams in two directions 
with rectangular slabs supported on each of 
its four sides ; (4) slab floor only carried at 
the column supports, so that the slab rests 
on four supports at each corner of the slab. 
1 5 pe 4 includes what the author calls his 
" Mushroom " system, the distinctive features 
of which are special reinforcement of the 
column caps, somewhat in the form of a 
mushroom head, together with the floor rein- 
forcing bars running in four directions, i.e.. 
two at right angles to one another in the 
direction of the lines of the columns and two 
crossing the rectangular floor slab diagonalh'. 
similar, in fact, to the arch ribs of a groined 
ceiling. In this way, by making the caps of 
the columns sufficiently large, the intervening 
floor space is coverefl with a network of rods 
running longitudinally, transversely and 
diagonally with the plan of the floor. The 
floor thus consists of floor slabs supported at 
their four corners and continuous over the 
points of support. The calculations for sue h 
slabs are somewhat complicated, but the 
author shows how the coefficient for the safe 
bending moment may be taken at a low figure. 
He also checks this by a large number of 
actual tests, showing that they agree closely 
with the calculated deflections. Deflections, 
except in the hands of a thoroughly competent 
engineer, are dangerous things to argue with, 
as they vary according to how the beam is 
loatled, and also in what manner the beam is 



supported; under uniform conditions, as the 
author shows, deflections may be made to 
represent .something tangible, instead of, as 
in the majority of cases, something that has 
been obtaine<l with much trouble and aff'ords 
little information in regard to the internal 
stresses that cause the deflections. The author 
himself seems to arrive at an erroneous con- 
clusion in regard to the efi'ect of deflections, 
for he saj s : "The most careful measurement 
placing standards in adjacent panels fails to 
reveal any negative deflection in the adjacent 
panels under loads of one and two hundred 
tons in the test of a single panel. Thus it is 
evident that there can be very little eccentric 
stress transmitted to the column." It may be 
rather that it is on account of the eccentric 
stresses in the column that the negative 
moment is not transmitted to the adjacent 
panels, but is absorbed by the columns. 

The author very rightly condemns the prac- 
tice of testing the floors before the concrete 
has been given time to become properly cured : 
such tests only weaken the structure and indi- 
cate rather what may be placed on the floors 
during the construction of the building than 
the ultimate strength of the floors. A chapter 
deals with the treatment of concrete made 
during extremes both high and low of 
temperatures ; this, together with a chapter 
dealing with the cost of the work, is of more 
value to American than English contractors. 
An interesting chapter is that in which the 
author describes how the surface of concrete 
may- be treated to give it an artistic finish ; 
like most of the materials employed by 
engineers reinforced concrete is utilitarian 
rather than decorative, and attempts to make 
it of pleasing appearance deserve encourage- 
ment. 

The book contains a great number of illus- 
trations, chiefly showing work during con- 
struction ; the author has also the courage to 
include some showing how buildings have 
collapsed owing to faulty designs. 



146 



r/.tONMBUniONAll 



}]Ii:m()Randa. 




I .tnJ Ncti'S Hems JW presenlea unJrr this heading, -with occasional eJilorUI 
Authentic ne'ws •Will be tvetcome. — ED, 



Painting Concrete Houses. — In a recent number of The BuiUlinii .W-.k's the 
followinj; two nu'lluxls of painting concrete liouses are given : 

Tlie first is lo mix colouring ingredients with the cement which will present 
lasting qualities, antl the second is to paint tlie exterior surfaces with some paint which 
will give somewhat similar results. The mixing of different coloured sands with the 
ccLiient to get colour-schemes, and the adding of certain oxides to the mixture to 
inlensifv certain shades, are still in the experimental stage. 

The difficulties in the way of applying colours to the exterior after the concrete 
house is finished are somewhat similar to tliose which apply to exterior painting of 
frame houses. The weather atTccts thcni and necessitates repainting at intervals. 
The use of lead and oil paints is not of lasting quality. The alkali of the cememt 
has an affinity for linseed-oil, and in time the oil oxidises and c^iuses the paint to peel 
oil or dust. Experimenters have realisetl for years that the ideal paint for concrete 
houses must he something more than a thin film. It must be a composition that will 
penetrate the surf.ice ;ind fill the pores, so that firm adherence can be obtained. .\ paint 
composed of colour-pigments, with ground cement .is the base, gives good results. 
The light chemic.il oils used are intended to dry out after performing their function 
of boniling the cemmt base to the concrete surf.ic<'. The cement base thus becomes 
a part of the wall and holds its colour indefinitely. 

When Nature, in the form of wind, rain, and sunshine has neutralised the alkalies 
of tlie cement it is much easier to paint the exterior structure and secure more dur.ible 
results; consequently it is unwise to figure upon having concrete houses p.ainted when 
finished. If lliis is intended the highest results cannot be expecte<l. Old concrete 
houses that have stood exposed to the weather for a year or two are in much Ix-tter 
condition for ]);iinting. The film of p.aint is w.-iterproof and hence checks the process 
of neutr.ilis.ition of the alk.-dies in the cement. If the house ha,s h.id an opportunity 
lo dry llioroughly the question of p.-iinling the exterior surface to get another colour 
can be considered with hope of success. 

Warrington Bridge. — The W'.irrlnt^ton Town Council have accepted the tender 
for this bridge, and have let the contract to Messrs. .\. Thorne &• .Sons, of Westminster, 
the bridge to be constructed on the Considere system of reinforced concrete. The tot.al 
number of tenders was twentv, and the two selected for final consideration were those 
of Messrs. Christiani & Nielsen, of ("o|x?nhagen, and the Considere Construction Co.. 
the latter company being granted the award. The total cost of the new bridge, which 
is to be So ft. wide, will be ^.14.310, including;- trainini^ walls, .and it will thus be one 
of the widest in Em;land. 

Tests of Reinforced Concrete Telephone Poles. — Mr. W. M. Bailey, in a 
paper read recentlv before the International Independent Telephone Ase;ociation of 
America, described a very thorough test of a concrete pole made in Richmond, Ind., 
as follows : 

" The pole was 30 ft. long .md embedded 5 ft. in the ground. It was 7 in. 
squ.ire at the top and 12 in. at ground line, and was thoroughly braced so as to make 



■47 



MEMORANDA. ICDNCBETE] 

it perfectly rigid. It was reinforced witli I'oiir |-in. twisted steel rods, li.uing an 
elastic limit of from 50,000 to 80,000 lb. per sq. in., and thoroughly bound together with 
No. 9 binding wire. With a horizontal pull of S40 lb. at the top the deflection was 
6 in. ; with 1,780 lb., 17 in. ; with 2,800 lb., 30 in. deflection, producing a slight cracking. 
The pole deflected 6 ft. before falling; the rods did not break, but the concrete crumbled 
and the rods bent over. .\ cedar |)ole of the same size deflected 11 in. with a pull of 
840 lb.; 33 in. with a jjuU of 1,780 lb., and broke 3'. ft. from the ground line with 
.1 i)idl of 2,200 lb. A concrete pole cm be buill for verv ne.arlv the same cost 
as a fust-class cedar jjole can he furnislud." 

Concrete for Motor Car Houses. — .\ recent issue of The Aiitucar gives sug- 
g-estions for tlu- ^andaiice of those who contemplate erecting a sjx-cial building for the 
protection of their cars. Sketches of suitable houses are g'iven ; the buildinjj to be 
erected upon brick sleeper walls, having Portland cement concrete foundations. The 
floor is made of the same concrete, si\ inches thick, floated over with cement and 
sand. If a pit is required in the motor-house they recommend that it should be 
formed of 45-in. brickwork in cement u]X)n a b-in. bed of cement concrete. The inner 
faces of the walls and the floor are to be rendered with a good coating of cement and 
sand. 

Reinforced Concrete for Machine Shops. — Reinforced concrete seems likelv to 
be fuLind very ad\'antageous in the construction of machine-shops. This material, 
as far as it concerns the machine-tool industry, was discussed at the recent Conference 
of the National Machine-Tool Builders' .\.ssociation, on which occasion Mr. J. P. 
Perry, of New York, pointed out the importance of the load-carrying capacity of 
reinforced concrete structures in this connection. It was remarked that reinforced 
concrete buildings are noted for their strength and their ability to safely carry 
unexpected loads. Floors have been designed to carry Ooo lb. |>er sq. ft., and have 
been subjected to 1,500 to 2,000 lb. live loads without the slightest indication of injury 
or increased deflection. 

Reinforced Concrete Power House. — A scp.irate unit type of reinforced concrete 
wall construction wa-- used list \e.u- in building the power-house of a small hydro- 
electric plant at Newton Falls, Ohio. The pilasters are of monolithic concrete, while 
the walls between them are hollow and are built of inside and outside thin concrete 
slabs, which were set before the pilasters were poured, so as to be keyed into them. 
The slabs were reinforced with No. 28-gauge expanded metal and were made in sizes 
that could be handled conveniently. Their outer surfaces were corrugated by laying 
|-in. round rods in parallel lines on the surface of the fresh concrete when the slabs 
were cast and pulling them out after the mixture had taken its initial set. These 
corrugations were designed to give a good bonding surface for the plaster coat which 
was applied to the walls after they had been erected. The slabs were allowed to 
cure and were then placed on edge in proper position. Vertical form boards were 
placed for the pilasters, extending beyond the surface for the monolithic work, so that 
the slabs rested against them. The inside f.aces of the pilasters were moulded against 
form boards placed in the air space between the wall slabs, and were wired to the 
outside forms after the pilaster reinforcement had been placed. The inside boards 
also acted as spaces to keep the slabs the proper distance apart. This distance varied 
somewhat, but 8 in. was the minimum. 

New York Water Supply. — The new Kensico dam, to be built across the valley 
of the Bronx river, and forming p.-irt of the general scheme whereby it is proposed to 
deliver to New York city a daily quantity of not less than 500 million gallons of water, 
will be a masonry structure 1,830 ft. long, with a maximum height of 170 ft. above the 
existing river bed, with foundations extending to solid ledge rock 120 ft. or more 
below the surface at the deepest point. Very large masonr\- and concrete blocks, with 
ornamental stone facings on exposed portions, will be used. When completed the dam 
will form a storage reservoir holding 40,000 million gallons, or approximately two 
months' supply, the flow line being at 355 ft. above mean sea level. The Eni^iiiccriiig 
Record states that the lenders for the work were 0[>ened on December 21. the lowest 
bid amounting to ;^i, 51)0, 600. 

Concrete Dams. — .\ writer in Cussicr's Magadne, on the subject of "Concrete 
Dams," says: "Among the iiiijKirtant structural problems which the civil engineer 

148 



f y, lONyrVIIl-l'ICINAn 



MHMORAXDA. 



is called upon lo solve one of ihe most proniinent, both by reason of cost and of 
consequence of ils results, is the masonry dam. It has be<Mi assumed that a dam ' must 
1h' secure aj,'ainst slitiinjj; on its base or any plane within Ihe b<xly of the dam, aj^.-iinsi 
overturning;, and aj^.-iinst crushinji of the materi.al at any point and consequent openinj^ 
of a seain at either face of the dam.' Compliance with these conditions has led lo 
the desij.jn and construction of great masses of solid masonry, capable by their wei>,rht, 
and by the friction of their bases upon the found.-ilion, of resistinjj any sliding; action ; 
and designed, as regards section, to compel the pressure to act at such ;i leverage as lo 
be incap.ihle of causing; failiue by overturninf^. 

" The .idvenl of concrete into i^eneral structural work, both in the plain .'uid the 
reinforced forms, has direct<'d attention lo the special applicability of this material 
for the construction of d.ams, and with the consideration of concrete as a possible 
material there has n.iturally come also an appreciation of the immense advantaj^je of 
a material which permits the control of the internal structure of the barrier. 

" It mij.fht seem as if the greater simplicity of the massive dam should t^ive 
it preference, at least in many instances, but, uixin examination, the masonry dam is 
seen to Ix- by no means the simple structure which it at first appears. The m.iss must 
be carefully compule<l and proportioned to prevent rupture or overturninj^ at times 
of maximum flood. The heavy burden involves a correspondinjj;Iy larj.je and deep 
foundation, with all the concomitant difllcullies encountered in the form of jjround 
w.iler, suhlerr.inean sprintjs and percolation. 'Ihe necessity for perfect union of base 
with found.ttion, both to prevent slidinjjj and to avoid the penetration of water, t.asks 
the ingenuity of engineer and constructor to the utmost. 

" The adoption of concrete as the material for dam construction has enabled many 
of the former dilTiculties to be overcome or minimised. By substituting a hollow for 
a solid structure the weight is correspontlingly reduced. This avoids the dangers of 
upward pressure, since any [lercolation into the interior cannot accumulate, but passes 
away gradually as it enters. Forces tending to cause failure by sliding or by 
overturning may be met by giving the structure such proixirtions that the resultant 
of all the forces due to any maximum head of water shall always p.'iss well within 
the base — ;i matter readily accomplished with such a material as reinforced concrete." 

The Society of Engineers. — The .Society of Engineers .will award a prize — 
designated " Th-j .Status Prize " — each year for the next four years (if papers of 
sutlicient merit are' received) for the best pajxr written by any |)erson on the subject 
of " How to Improve the Status of Engineers and Engineering, with special reference 
to Consulting Engineers." The prize will consist of books and (or) instruments, of 
Ihe value of three guineas, to be selected by the author of the essay gaining the award. 
The regulations governing this prize are as follows : — 

The essay shall^be Written in the third person, shall contain not fewer than 4.000 nor more 
than*6,ooo words, and shall be typed on one side only of foolscap paper, the distance between 
the lines being I in. or more. 

All essays submitted in competition for this prize and the cop\Tight therein shall become 
the property of the Society, but the donor also shall have the right of publishing such essavs or 
any part thereof. 

The Council of the Society may, at their di-icretion, permit the publication of any essay by 
its author, on such conditions as they may think lit to require. 

The premiated essay shall be read and discussed at a meeting of the Society, the reading 
being done l>v the author if possible, and such essay shall be published in the usual manner in 
the Society's Journal, the author being entitled to recei\'e 50 copies of his paper upon publication 
thereof. 

The prize shall not be awarded to any Member of Council or Officer of the Society. 

Essays sent in for competition must be received by the Secretary on or before May 31st. in 
each year. 

National Association of Cement Users. — The si.xth annual Convention of the 
National .\ssociation of CennTit L'sers of .America (Mr. Richard L. Humphrev, 
M..\m.Soc.C.E., President) will be held on February 2ist-25th ne.xt at Chicago, L'.S..\. 
The Convention has been arranged to take place during the Chicago Cement Show, 
which will be held from February i8th-26th. The association have extended invitations 

149 



MEMORANDA. 



[CONCRETE] 



to concrete associations in England and abroad, and the Convention uill therelore 
have an international significance, and will be one of the largest gatherings in the 
world in the historv of the cement industr\-. The Mayor of Chicago will open the 
C"onvention, and the following are among the matters which will be discussed : Report 
of the Committee on "The Exterior Treatment of Concrete Surfaces"; the Use of 
Concrete for Farm Buildings from the Sanitary Standpoint; Laying Concrete under 




Water; Concrete for Maritime Structures; Application of Concrete in Barge-cana 
Work; Comparative Cost and Efficiency of the Pneumatic Reinforced Co™:rete Dam^ 
Additional Notes on the Use and Cost of Concrete for Small Houses There vv.ll also 
be a report of the Committee on Building Laws and Insurance, and a report ot the 
Conimittee on Specifications for Fireproofing. 



MEMORANDA. 



TRADE ANNOUNCEMENTS, CATALOGUES. ETC. 

The liritlsh Vrallte Co., Ltd., 16 St. Helen's Place, B.C., have laluly 
pI.H'i-d (111 llu- iiiarkil .1 >.)iiii |j|a>ltr-a>l)i-.l(>s i).irliliiiii. Ihe) have- been successful in 
securing a iiumiIkt of contracts for tlieir " Lralile " and " .\sbcstone " for the walls 
aiKi roofs of many of the new sU.itinf,'^ rinUs now beinji; constructed all over the 
country. .\t their recent Annu.il Meetiii)^ the ("h.iirnian announced that the sales of 
the British L'r.ilite C"oni|),iny's ni.iterials h.id incre.iswl by 21 [kt cent, durinj.; the 
|)eriod from July 1st to December ,^isl, i<)o<). 

The Building and Estates Development Co., Ltd., of Bristol, h.ive sem 
us .in illustralctl |)ani|)hlcl dc>cri|)li\e of their system of concrete construction, ,ind 
emphasise the fact th.il under this method it is |X)ssihle to build monohthic-concrete 
walls with both verticil and lonf;;iludin.il cavities or air spaces, and al.so thorouj^hly 
to bond the walls transversely. The patentees cl.iim ih.it .a considerable saving in 
cost may be elTecle<i by the use of this sytem, which .also obviates the necessity for 
lining the outside walls, as a thoroughly insulated w.ill is formed by a combination of 
air chambers being^ given according to the width of the w.ill. A section of .1 concrete 
roof is shown constructed on the cavity system, the smoolh surface of which makes it 
.available for roller skating. The company are the sole patentees in this country, but 
we believe th.at foreit^n riijhls may be obtained. 

The Cubitt Concrete Construction Co., of Gray's Inn Road, W.C., have 
issued an interesting p.imphkt respect inj,-^ " Medus.i " water-proofing material, for 
wliich they are sole London agents. This comixjund, which has now been on the 
iii.irket for several years, would appear to have .a very universal application if one may 
judge from the list quoted of Government olVices, public buildings, and other institu- 
tions in which it has been used. Intended for practical use under the ordinary con- 
ditions of building construction, it is claimed for " .Medusa " that, when added in 
very small quantity to Portland cement, it makes mortar, gr other mi.\tures of sand 
and cement, used as :i rendering imiK'rvious to water, .and will greatly extend the 
field of concrete-construction o|>er.itions. S|x.'cial utility is claimed for this prepara- 
tion in the making of building blocks, cistern and reservoir linings, sewer pipes, 
conduits, roolini; tiles, cellar walls, and in other uses where resistance to the percola- 
tion of water is essential. , 

In addition to photographs of buildings treated with " Medu«ia " compound, 
testimonials as to' its elllc.icy, and particulars of some water absorption tests, there 
are also given some useful instructions as to the mixing in correct pro|X)rlions .and 
application of the material as a rendering coat. 

Expanded Metal In Australia. — li\\>;auU%\ metal has been used in the new 
Cold .Storage Buildings of the (ieelong 1 l.irbour Trust. It was also used (in conjunction 
with Kahn bars) for the entire work of floors, s^irders, and circular staircases of the 
new ("hemicil Laboratory for the .\ustralian Commonwealth erected in .Melbourne, 
Nictori.i. In this work an interesting test was applied by placing 3 ft. of sand 
o\er the whole area under test. The span of the main girders was 30 ft. between 
bearings. The extreme dellection res^isifred w;is ,^,.-in., I)ut in most cases it registered 
3^ -in to i-in. 

Stuart's Granolithic Co., Ltd.. of 4 Fenchurch Street, E.C.. inform us th.u the 
concrete staircases at Messrs. .Arding &• Hobbs" premises which withstoixl the recent 
lire so well, and which are still in good condition, were supplied by their firm. 

Engineering and Machinery Exhibition at Manchester. — This exhibition, 
which is promoted b\- The Knginccriiii^ Rcvim', will tie lu-ld at the City Exhibition 
Hall, Liver|xiol Road, De.insi^ate, .Manchester, from Octol>er 14th to Xovember 5th, 
K)io. We underst.and th.-it s|)ecial arrangements have been made for the convenience 
of exhibitors in connection with power, lighting, stand-erecting, etc.. the lowest 
possible figures being charged for all facilities of the kind. 




CONCeETE 




A Fireproof 
Asphaltic 

Roof 
Covering. 

Economical. 
Permanent. 


Graves' Patent Roofing 

FOR ROOFS OF ANY PITCH, AND 

FLAT ROOFS 

WOOD OR CONCRETE 


1 4-0 Years' Experience. | 


Illnvi, jt, ,1 r.italoMir aii.l full |..irt,cul.irs from 

GRAVES & CO., LTD. 

Finsbury Court, Finsbury Pavement, London, E.G. 

LIVERPOOL: Oriel Chambers, Water Street. 
GLASGOW: 45 Hope Street, WATERFORD : (Head Office). 



EDITORIAL MEMOS. 

CONTRIBUTIONS.-OriKinal contnbuiions and 
illustrations are specially invited from engineers, 
architects, surveyors, chemists, and others engaged 
in practical or research work. MSS. should be written 
on one side of the paper only, giving full name and 
address of the author. 

The copyright of any matter accepted for pub- 
lication is vested solely in the proprietors of the 
journal to be used in any form they think fit. unless 
there be a special arrangement. 

MSS. and drawings or photographs are sent in at 
the author's risk. Every eflort will, however, be 
made to return unsuitable communications. 



PUBLISHER'S NOTICES. 

;S OF ISSUE.— This Jourral is issued 
For Advertisement Rates apply to Pub- 
batter forciisplayed advertisements required 
of inontfi iirior to subsequent issue, for 
olumn by IStli. 



SUBSCRIPTION RATES (Prepaid. -Post free). 
Great Britain, the Colonies, and all Foreign 
countries. I 2/6 per annum. 

The Triennial Subscription is 35/- (three years), 
."iddre'is remittances to Concrete Publications. Ltd, 



> Londo 



1 News Company 



NOTICE. 

THE world's history of Concrete and Reinforced Concrete can 
be best read by purchasing "Concrete & Constructional 
Iingineering." 
We can supply post free, upon remittance with order, the following 
back numbers — also hidices, Binding Covers and Bound Volumes. 



BACK 
ISSUES 



Vol. I. No. 4, Price 2/6 each. 

Vol. I. Nos. 5 and 6, Price 1/6 each. 

Vol. II. Nos. 1 to 6, Price 1/6 each. 

Vol. III. Nos. 2 to 6, Price 1/- each. 

Vol. IV. Nos. 1 to 7, Price 1/- each. 



nd 3. and Vol. 111., A'o. 
are out of i>rint, but 



ible at 51- each. 



INDICES for Volumes I., II., III. and IV. will be sent on receipt 

of penny stamp for postage. 

BINDING COVERS for Volumes I., II., III. and IV. with Index 

will be sent post free on receipt of 2/- each. 

BOUND VOLUMES: Vol. I., £1 Is. ; Vol. II., 10 6 ; Vol. III., 12 6 ; 

Vol. IV., 10 6. 



al orders (prepaid) are taken at 35/- post free, as well as ai 

orders at 12/6 post free. Triennial orders (prepaid I economise postage and book-keeping. 

Address Orders : The Publisher, Dewar House, Haymarket, London, S.W. 

Remittances should be crossed "Cocks. Biddulph & Co." 



CONCRETE 

AND 

COT^STRUCTIONAL ENGITSEERING 



W.lume V. No. J. I.mnixin, Makch, 1910. 

KDITORLIL NOTES. 



SPECIFICATION FOR PORTLAND CEMENT. 

Tl I li news that tliL- lingitucriiii,"^ .Standards Comniittcc may at an early 
date issue a turthir revision of their specitication for Portland cement 
calls attention to the general improvement in the quality of Knglish 
ctment and the better understanding which has undoubtedl)' arisen between 
engineers, nianulacturcrs and users since tlie Committee was instituted in 
i()04. 

Ail who are interested in the subject are aware that Portland c<'ment is 
essentially a British invention, though few may realise tlje fact that its utility 
has been recognised for at least eighty years since its first production in this 
country. 

Just as in the history of the gentler arts there ha\e been intervals of 
neglect followed by periods of renascence, so in the history of Portland cement — 
now recognised as a material of world-wide importance — the stimulus given to 
improved methods of production by the specifications of engineers, such as the 
late Mr. Grant in i860 and Mr. (i. V . Deacon in 1875, was followed by a 
long interval during which but little ad\ ance was made. 

W bile the despised foreigner, with the aid of chemistry and the adoption 
ol impro\enients in grinding machinery, was diligently employed in gaining a 
position for his product in tlie markets of the world the British maker of 
cement, as a general rule, seemed content to rest on his laurels; while the 
user of cement, although very often himself in fault, made haste to attribute 
e\cry failure to the manufacturer whose methods were often enshrouded in a 
\eil of impenetrable mysterw 

Those who can look back to the history of the trade during the past 
twenty-five years will recollect that at this conjuncture there appeared upon 
the scene that useful but often maligned person, the professional cement 
expert. Meanwhile, the architects and engineers, who were inclined to be 

>53 



CONCRETE INSTITUTE MEETING. 

sceptical of the doctrine either of the esoteric or exoteric schools of thought 
represented by the cement maker and the expert, and, moreoNcr, unwillint; to 
occupy the position of the person in the famous triantjular duel whose unenvi- 
able lot it was to be fired at by both the other combatants at once, held aloof 
from the controversy, drew their own specifications and had their tests carried 
out bv anv of their staff assistants who could be spared for the purpose. 

How different is the position to-day, when engineers, architects, experts 
and manufacturers co-operate to raise the standard of English Portland cement. 
It is an undoubted fact that the old exclusive attitude of the maker to the 
user has entirely changed, and a friendly invitation to the latter to visit the 
works and inspect the Duultis operandi from beginning to end has now become 
an t)rdinarv incident of the trade. 

Meanwhile, the ([uality of British Portland cement during the last decade 
has vastly impro\ed, so that it has again become pre-eminent in the world's 
markets, and its rc]iutation llierelore stands higher now than at an\- period 
of its history. 

CONCRETE INSTITUTE ANNUAL GENERAL MEETING. 

We have leceived particulars as to the first annual general meeting of the 
Concrete Institute, which was held at the Royal United Service Institution on 
February 17th, the Rt. Hon. the Earl of Plymouth, C.B., President of the 
Institute, in the chair. We have also received a copy of the .Annual Report, 
which we publish under " Memoranda " in this issue. 

The Institute are to be congratulated on the excellent progress made 
during their first year of incorporation. The fact that the membership now 
numbers over 850 is eloquent testimony to the usefulness and need of such a 
body. 

The work ol the Institute has been in the right direction and well merits 
t)ur praise. The papers presented ha\ e been uselul ones, and the discussions 
more than usually interesting. 1 he \ isits to \ arious works and places of 
interest have been instructive, but what strikes us as being of most importance 
is the work done by the standing committees, who even at this early stage 
have been performing excellent services in the interests of concrete and 
reinforced concrete both on the scientific and legislative side. 

As to the Council lor the current year, we are pleased to note 
that Mr. C. H. Colson, M.Inst.C.E., Mr. J. -S. E. De Vesian, M.lnst.C.E., 
and Mr. William Dunn, F.R.I.B.A., iiave been re-elected, and the Council 
are also to be congratulated on the new members added to their number — - 
namely. Professor Henry .\dams, M.Inst.C.E., Mr. E. Fiander Etchells, 
F.Phys.Soc, and Mr. W. G. Kirkaldy, .\ssoc. M.Inst.C.E., whose services 
will no. doubt prove of great benefit to the Institute. 

We are also glad to see by the annual report that the finances of the 
Institute are in such a satisfactory condition, in spite of the heavy expenses 

'5^ 



LOCAL GOVHRSMHXT HOARD. 



ol IiH-oiporalion ami I'arliamcntarv action, Ixjth heavy items in the first 
year ol an institution ol this kind. 

Ihc annual rqxirt throws out sugj^cstions as I > fuluri- (l(\ i-lopments, 
anions^ others that branches of the Institute be formed in pro\incial towns, 
and I hat a Graduate section be formed of juniors who arc anxious to study 
technical matters in concrete and reinforced concrete. It will be interesting 
to observe how these suggestions are taken up. 

LOCAL GOVERNMENT BOARD AND REINFORCED CONCRETE. 

W'k ha\e from time to time ref( rred to the grievances of local authorities and 
others regarding the shortness of the loan periods granted by the Local Govern- 
ment Hoard for reinforced concrete structures as compared with the periods 
alk)W((l on other building materials. 

We have strongly advocated that an independent committee on the subject 
should be formed, representative of the various Go\ernmenl departments who 
have used reinforced concrete, local authorities and the professional institu- 
tions concerned. 

The grie\ance has again been forcibly brought to our notice by an excel- 
lent letter on the subject which has been sent us by the Patent Indented Steel 
Har Company, .\lthough such a letter obviously might have Ixirne more 
weight if it had emanated from a professional body, still it states the case 
M-ry clearly, and we publish it in full and recommend it strongly to the atten- 
tion of all concerned. 

" The .ittitude of the Loc.il (iovernjiient Board or their Engineer in refusing 
to allow loans to local authorities for the construction of works in reinforced 
concrete on the same terms as in cases where other materials are used is, by this 
time, sufficiently notorious. But we think that the hardship inflicted upon small 
local authorities, and upon firms such as our own, whose business it is to design 
or carry out work in the material, is not fully appreciated. 

" We should like, therefore, to call attention, to a recent case (which is far from 
beiTig an isol.ited one) in which we have received a letter from our client stating that 
he has just been informed by the Local Government Board that only ten years can 
be allowed for a loan with which a reinforced concrete tank was to be constructed, 
and that, therefore, the project must be abandoned. Several designs for this 
tank have been prepared by us, and negotiations have been continued between 
the contractor and our client and ourselves for some months; \et, when these 
have been brought to a conclusion that is eminently satisfactory' to the would-be 
owners of the tank, owing to the economy both in original cost and upkeep of 
reinforced concrete as compared with any other material, the whole of the trouble 
and expense is absolutely thrown away by the action of the Local Government 
Board. In addition to the waste of labour thus caused, the Local Government 
Board are preventing the local authorities in question from reaping the benefit 
of the economy and other advantages of this material. 

" That such advantages do exist, and are not merely the product of imagination, 
is sufficiently proved by the action of the .Admiralty, War Ofl'ice, Board of Works, 
railway companies and large commercial firms, who have to such a large and 
increasing extent embarked upon the use of reinforced concrete. 



LOCAL GOVERNMENT BOARD. [CDNCBETE] 

"It is absurd to suppose that such bodies would adopt a material whose life 
was supposed by their technical advisers to be only ten years. Up to the present, 
■deputations, correspondents, and personal interviews have all met with the same 
fate and have proved to be utterly ineffectual in obtaining the necessary con- 
sideration. 

"The President of the Local ("lovernment Board is, no doulit, ruled in these 
matters by his chief technical adviser, but surely when the consensus of profes- 
sional opinion is so clearly against the advice which appears to be given to him 
it would be to the public advantage if a committee of independent experts were 
appointed by the President of the Local Government Board to advise him as to 
whether the action of his technical adviser is in accordance with the accepted 
opinion of the engineering profession or is the outcome of a more or less personal 
bias against the particular material in question." 



FTTc 



SWANSEA. 








~ -?^- 

»&--,^ 



REINFORCFD CONCRETE 

QUAYS AT KING'S DOCK, 

SWANSEA. 



The neiii Dock al Sivjnsej, ivhich vus opened In Nmiemter of last vejr, is one of Ihe 
most Imporljnt enterprises ever uriderljken t'y Ihe Bristol Channel Aulhorlties, Mid -will 
brina Swansea. In the course of the next fe-w years. Into the first rank of export ports In 
the Untied Kinqdom. ^ 

In this article vie are dealing -with Ihe reinforcea concrete quays -which ha-ve teen 
erected on the north side of the coaling arm for a length of 7£0 ft., and also for Ihe coaling 
■wharves on the south side, 1138 ft. in length. 

The particulars contained in this article, as -well as the photographs illustrating it. -were 
placed at our disposal by members of the Resident Engineer's Staff. - -ED. 



A.MONc.sT the many new ami im])(ntanl features eomprised in Swansea's 
/2,ooo,ooo dock, which was formally opened in No\'ember of last year, there are 
none which show a greater advance in constructional practice than the two 




rem forced concrete quays which are designed to carry coal hoists of the latest 
jiattern, both fixed and movable, capable of giving the utmost dispatch to vessels, 
whether bunkering or loading whole cargoes. 



KINGS DOCK, 



[coNCBKin:! 



4 



< 




i?8 



SWAXSHA. 




•59 



KING'S DOCK, 




g m 

B S ' 

a m ■ 

B a ■ 

-o B s ■ 



[CDNCBET Ej 

A glance at the l:ey-plan in I-ii:,. i. uf 
Swansea Harbour, will show the encrmnus 
addition made to the docl: accommcdation by 
the linngint; into use of the new King's Deck 
and the prominent position in the arrangement 
given to the reinforced concrete ccaUng quays- 
In the original designs it was intended to 
ha\-e fixed hoists only, placed at intervals along 
the quay wall upon concrete and mascnry 
piers, with pitched slopes in between them, 
br.t as the scheme advanced, and the Great 
Western Railway Company took a frontage of 
1,000 [t. on the nrrth side of the deck, it was 
decided to include a quay for movable heists 
between the projecting piers for the fixed heists. 
A design in masonry construction was 
prepared to deal with these new machines 
m the form of a series of longitudmal arches 
extending about bo ft. back fr> m the quay 
line, but owing to the uncertain nature of the 
foundations the cost was held to be prohibitive, 
and the engineers came to the conclusion that 
a reinforced concrete quay would be mere 
economical and efScient than any ether kind 
of construction. 

In the meantune the Midland Railway 
Coinpanv had tal:en a frontage of 700 ft. on 
the south side t-f the d(;ck, and the Rhondda 
and Swansea Bav Railway Ccmpany already 
had an option with regard to another strip 
(,f quay. The Harbour Trustees, therefore, 
decided to construct a second reinforced 
concrete wharf on that side of the dock, and 
t-, include a liberal accommodation for then- 
own purposes. 

The engineers (Mr. P. W. Meik, M.Inst.C.E., 
of Westminster, and Mr. A. V. Schenk. 
MInst.C.E.. the Engineer-m-Chief to the 
Swansea Harbour Trustees) then elaborated a 
quay scheme for b..th sides of the dock, which 
is in some ways a departure fr.m previous 

practice. 

It will be noticed that at intervals along 
the quavs there are projecting piers on tip- 
heads and that these severally fall behind one 



160 



r y. CGN.vrPlKTIONA 1 .1 



SWANSHA. 



another. By this means a vessel, however long, being loaded at one tip, is free to 
( hange its position to any extent for convenience in loathng into any of its 




I'u.. 5. PhiAiL Sections 




ric.. 6 Front Im.evati. 



hatches, without in any way interfering with other vessels which may at the same 
time be loading at the adjoining tips. 

i6i 



KING'S DOCK, 



ICQNCBETEl 



By this arrangement the great inconvenience which is mx'ariably experienced 
at " in-line " coahng quays is entirely obviated. 

Between the projecting piers are the continuous quays for the movable 
hoists. Vessels, when moored at these quays, will again be quite clear of those 
at the projecting quays, and can be served simultaneously by two, or even three, 
hoists, thus expediting the loading of coal cargoes in an extraordinary degree. 
Added to the fact that the hoists themselves are designed to work at a speed 
of i8o ft. per minute, and are served with 8-in. diameter hydraulic mains, it will 
be seen that the Trustees have dealt with the matter in a liberal and far-seemg 
manner. 








^%r 



>i;.; 



Fig. 7. South Side of Dock. REiShORCED Concrete Qcay nearing completion. 

When the south quay is fully equipped it will be possible at one time to 
load, at the fixed tips, five of the largest class of ships that can enter the lock 
(the dimensions of which are 875 ft. by 90 ft.), and four other vessels at the 
qua3's served by seven movable hoists. 

At the Great Western quay there are now being erected three fixed and two 
movable hoists, which will allow for the loading of three and sometimes four of 
the largest vessels at one time. 

The length of the north-side quay is 1,000 ft., and that on the south side 
about 1,800 ft. 

The depth of water in the dock is usually kept at 35 ft., and the height 
from the dock bottom to the quay le\-el is 41 ft. 

The construction of the two quays being very similar in character, a brief 
description of that on the south side only will be necessary for the purposes of 
this article. 

162 



>■ moiMtJjiiNo —J 



SWANSEA. 



The tuuiKlalioiis of the structure were mainly in gravel, of varying hardness. 
wliiist in some cases clay pockets were met with, which required certain varia- 
Iiuiis ill the design. In one or two places the gravel was so hard that piles could 
iKil l)c driven through it, concrete slabs being substituted in which dummy i)iles 
were embedded. 

The quays for tlie movable hoists arc divided into bays of about 30-ft. span, 
and consist trans\ersely of a front and back column square in form, 4 ft. in. by 
4 ft. 6 in., with a base slab 8 ft. b in. square. These two columns come under 
tiic treads of the moving hoists. Behind the back columns two rows of piles are 




ancrete quay under construction. 
s AT King's Dock. Swansea. 

<lriven, forming the supports for the fi.xed traverser gantries, along which the 
traversers carrying the coal trucks will run to feed the movable hoists in their 
\arying positions. The back row of piles also forms an important part of the 
curtain wall which retains the embankment at the back of the quay. 

At a height of 25 ft. above the dock bottom the columns are strutted and 
braced both longitudinally and transversely, to give bearing for the beams which 
carry the decking. 

The decking generally is 5 in. thick, and is carried on joists 3 ft. 9 in. apart. 

The general dimensions of the structure are detailed on the accompanying 
jilans. 

The piers for the fixed hoists are of similar construction to the continuous 
quays, with the addition of piles for carrying the legs of the overhead gantries 
which connect the storage sidings with the hoists. 

163 



KING'S DOCK, 



[CONCRETE] 



To protect the surface of the decking from the action of the sun and the 
we;ather the whole is covered over with a layer of broken stone, topped up with 
another layer of ashes. The decking is jirovided with weep-holes, so that the 
quay is perfectly dry at all times. 

The dock face of the structure is jjrotected throughnut with elm fenders 
bolted to the columns and longitudinal bracmgs. 

Reinforced concrete i|iiay for G. W Kly. 





Fig. 9. Reinforced { 
Reinforced Coscretf. Qlavs at King's Dock. Swansea. 

The quays have been designed to carry the following loads : 

Fi.xed hoists : 200 tons on front of hoist, 140 tons on back. 
Movable hoists : 200 tons on front of hoist, 140 tons on back. 
Wheel base of ni(i\-able hoists : S ft. in. — 18 ft. 10 in. — 8 ft. 6_in. 

164 



^EN(,INt.lJ<lN(. ~J 



SWANSEA. 



Traverser gantry : mi pillar. 50 tons ; on girder, 30 tons at centre. 

Decking of wharf : > cwts. per sq. ft. between hoist lines ; 3 cwts. elsewhere. 

In a<lcliti(in to the main quays, three of the approach-line gantries have l)ecn 

constiiutcil 111 reinforced concrete, with which arc incorporated the foundations 

for turntables, weighbridges, and wcigluabins for dealing with the coal coming 

on to the hoists. 

The aggregate from which the concrete was made is as follows : — 

27 cu. ft. of clean Guernsey granite chippings (between i in. and j in.) ; 
13,^ cu. ft. of screened beach sand, from i in. downwards : 
and 7 cwts. of Portland cement. 
Such a mi.xing resulted in 31 cu. ft. of concrete in the work. 
E.xix'riments were made by Messrs. Kirkaldy to ascertain the crushing 
resistance of twelve 6-in. cubes made from the above aggregate, the cement 
being made in a rotary kiln by the Knight, Bevan & Sturgc Branch of the 
Associated Portland ("(-meiit Manufacturers (iqoo), Ltd. 

Crushed at Tons, 
per s 1. ft a\erage. 

3 blocks broken at the age of 3 months ... ... 245'i 

3 .. .. .. '' .. 272-5 

.5 ., „ .. ,. 299-9 

3 .. .. .. 12 ,. 315-2 

An experiment was made during construction to test the strength and 
soundness of a 14 lu. by 14 in. pile, which could not be driven to its specified 
depth, owing to the hardness of the ground. The pile was driven to the ordinary 
set with a two-ton monkey falling 6 ft., with the patent Hennebique helmet on 
the head of the pile. It was then hammered home with -an increasing drop, 
until a dro]i of nft. was reached. .Mthough the helmet was badly damaged, 
the head of the pile suffered in no jiarticular, with the exception of a slight 
S])rawliiig at the arrises. 

The details of the construction were designed by Messrs. Mouchel & Partners, 
of X'ictoria Street, S.W.. and the work was carrietf out by Messrs. Topham, Jones 
& Kailton. Ltd.. of Westminster, who were the contractors for the whole dock 
scheme. The speed with which they carried out the work testities eloquently 
to the i)erfection of their organisation. 

The north quay was commenced in October, 1907, and completed in June. 
1908 : whilst the south quay was started in April, 1908, and finished in April, 
1909. 



16; 



ALBERT MOVER. 



1CONCRETE3 




POSSIBILITIES OF THE 

USES OF 
MINERAL OILS MIXED 
WITH CONCRETE. 



By ALBERT MOVER, Assoc.Am.Soc.C.E. 



The article we are presenting herei 
Assoc.Am.Soc.C.E.f tvho is a tvetl-knoiv 
concrete* The subject, of the effect of 



lith has been sent us by Mr. Albert Mayer, 
■t American authority on all matters relating to 
nineral oils on concrete, has been attracting 
considerable attention in the American Technical Press, ana Mr, Logan W. Page is 
conducting extensi've ini>estigations in the Laboratory of the Office of Public Roads at 
Washington on the matter. A great deal yet remains to be learned concerning this method of 
preparing concrete 'with oil, but 'we hope before long to recei've more information on the 
sublect. —ED. 



TiiK mixiiii,'^ of iniiura! oil willi concrcti* is very simple. Tlie (lil, alkalies, and water 
will form an emulsion hecomintf thoroutjhly incorjxirated in the concrete. If thie 
concrete is to be mi.xed by hand, proceed as usual, and, after the water has been 
added and the .resultinjj mass turned and raked, add non-volatile mineral oil in 
proportion of lo to 15 per cent, of oil to the weight of the cement. Turn the concrete 
with shovels two or three times, raking while turning; the oil will quickly emulsify 
and become thoroughly mixe<l in tlie concrete. 

If machine mixing is cmploM-d, use a batch mixer, turning a sutTicient number 
of times to thoroughly mi.x the cement, sand, crushed stone or gravel, and water. 
Then add 10 to 15 per cent, of non-volatile mineral oil. Turn again the same number 
of times as it requires to mix the concrete; the oil will quickly emulsify and become 
thoroughly incorporated in the concrete. 

Oils added to concrete in proportions of from 5 to 15 ]>er cent, will slightly delay 
the inili;tl and final set. Increasing the proportions of oil will further retard both 
the initial and final set and hardening, but up to 15 |)er cent. From experiments so 
far made, it would seem that the retarding of hardening will not be sufficient to cause 
the work to be uneconomical. 

The tensile strength will necess.irily be reducetl, and with the increasing percent- 
ages of oil toughness will be slightlv diminished, but not in proportion to the increase 
in the percentage of oil used. 

An extremely interesting paper was recently read at the meeting of the Association 
of .American Portland Cement Manufacturers by Mr. Logan Waller Page, Director, 
Office of Public Roads, Agricultural Department, \\'ashington, on the subject of the 
possibilities of Portland cement as a road material, in which he described some 
investigations being carried on by Dr. Allerton S. Cushman in the Laboratory of the 
Office of Public Roads to ascertain the practicability of mixing semi-asphaltic base 
oils with Portland cement concrete, with the object of obtaining the desirable properties 
of both Portland cement and asphaltum. So far, only i)ats and briquettes have been 
made;. the results so far obtained show ample strength for ordinary work; 6-in. 
cubes will be tested later. 

It is believed that compression tests will show greater strength than the usual 
relation of compression to tension. This is a matter for further investigation, and 

166 



OILS MIXED WITH CONCRETE. 



it i- lo 111- Iui|xhI that clu-inisls and ccim-iil Ic-iters will actively take up lhi> work and 
canv <)[i investi(ialions coverinj^ loif^ time [periods. 

I't'nsile strain tests should be discarded. Such tests have now been discardt-d by 
the (ierman Portland cement manufacturers and compression tests substituted. With 
the increased scientific Unowledije and the consequent better material produced by 
I'ortland cement manufacturers tensile strain tests have become obsolete, and, owinfj 
to the brittleness and extreme sensitiveness of neat Portl.and cement and the unscientific 
methods employed in tensile strain tests, these tests do not indicate the |X)ssible load 
which Portland cement-concrete may carry. 

The author, therefore, w'ould e.irnestly .idvocate compression tests on cylin<leTS 
of a size which will cause the area to equal ()-in. cubes. In order that such tests may 
be standardised and relative, standard sand should he used, and, if possible, a 
standardisation of fi;ravel or crushed stone. If crushed stone, trap rock should be used, 
.ill p,issinf»^ throutjh a |-in. mesh and all collected on a ^-in. mesh. Mix up cylinders, 
which will theoretic-lily fitjure maximum density, add varyinff proportions of oil from 
5 to 20 per cent. .Mso m.ike up another set of cylinders, addinj.; varying proportions 
of hydrated lime from ui to 30 per cent., increasinjj the percentage of oil with the 
increase of hydrated lime. The addition of hydrated lime theoretically should permit 
tlie addition of a Larger pc'tcentajjfe of oil, as we thus have a greater emulsifying 
material. Varying jiercentages of Portland cement may he used, always keeping the 
relation between the sand ;ind stone the same, maximum density having been figured. 
The amount of Portland cement to he increased above that which is required lo fill the 
voids in the sand. 

.'\ few months ago ihi' wrilcr ni.ide some hriqueltcs .ind p.ils with the object of 
ascert.-iining if the mixture of oil wilh wet neat cement .ind murl.ir would h.ive the 
tendency of keeping .ill but llie excess water from leaving the wet neat cement or 
mortar. 

Briquettes were made, neal ceiiienl mixed wilh water, the water slightly in excess 
of that usually required, after whicli 10 [)er cent, of oil petrole was added. (Oil ix'.role 
is a while non-volatile petroleum product of about the consistency of melted vaseline.) 
Pats were made of i part cement, 3 parts sand mixed with water, a little in e.xcess 
of what would ordinarily be used, after which 10 per cent, of the same oil was 
added. These pats .ire about 2^ in. in diameter and rl in. ihick. 

.\s soon as made they were left in dry air, the inrtial and final set was found to 
be normal. They were never immersed in water, but remained in dry air for sever.il 
weeks. \o cracks occurred, and they beaime so hard and strong that these pats — 
i in. thick — were very difiicult to break by using the fingers and thumbs. .\fter 
remaining in dry air for three weeks they were put out in freezing temperature for 
three days, and again pl.icetl in drv air over the r.adialor. No cracks or checks have 
occurred. 

.\ftor remaining in drv air for a month a lest for absorption was m.ade. .\ broken 
pat was weigluxl dr\ and found to weigh ;,|_{ 11/. It was then immersed in water for 
several hours. L pon removal from the water the surf.-ice was quicklv removed wilh 
blotting paper, the pat imme<liatelv weiglied .uid found lo weigh ,V| oz. Only ,■f^ oz. 
of water was absorbed. 

The fact th;it the pals were never immersed in water and showed no evidence 
of checking or cracking, and became hard, would indicate that the emulsified oil had 
held the water in the mortar and that such mortar was, therefore, both non-evapora- 
tive and non-absorbent, which would tend to show that concrete in which mineral 
oil has been mixt-d would not be likelv to contract and therefore contraction cracks 
avoided. 

L'nder the theory of Prof. Baiivchinger, which has been demonstrateif by Prof. 

.67 



ALBERT MOVER. [CQNCBETEJ 

Swain in the Laboratory of the Institute of Technolog-y, Boston, neat cement when 
set and hardened in air contracts, and this contraction increases with age up 
to a certain period, possibly six months or a year, i part Portland cement, 3 parts, 
sand hardened in air shows contraction, but less in proportion than neat cement. The 
results also prove that neat cement when hardened under water shows a slight 
expansion, while mortar composed of i pari Tortland cement and 3 parts sand, 
hardened under water, shows expansion, but less in |)roiX)rtion than the neat cement- 
Reducing- these conclusions to figures and t.iking the average results obtained by 
various authorities, figuring the expansion and extraction by [X-rcentage the following: 
are the results : — 

Neat Portland cement hardened in air .U the end of 16 weeks shows -15 per cent. 

contraction. 
1 to ', mortar hardened under water .it the end of 16 weeks shows "05 per 

cent, contraction. 
Neat Portland cement hardened under water at the end of 16 weeks shows 

•05 per cent, expansion. 
1 to 3 mortar hardened under w.iter at the end of 16 weeks shows a -015 per 
cent, expansion. 
Mixing oil with concrete from the meagre tests so far made would seem to 
indicate that the oil held the water in the mortar, keeping the cement particles wet, and 
thus furnishing the same conditions as if set under water, hence very materially 
preventing, if not altogether obviating, contraction cracks and hair cracks. Further- 
more, the resulting mortar appears to be far less brittle, and therefore such treatment 
should admirably serve the purposes required for concrete retaining walls, foundations, 
enclosing cellars, tanks, cisterns, etc. 

Exhaustive tests have been made bv a number of authorities on the action of 
oils on concrete. The effects of oil on concrete and the effect of oil emulsified in 
concrete are two separate and distinct subjects. 

We are informed bv reliable authorities that concrete immersed in animal or 
vegetable oils will in time disintegrate and that concrete immersed in mineral oils 
is Unaffected In the first instance there was no chance for the oil to emulsify; in the 
latter the oil is separated into minute globules. .\ large field of usefulness is ready 
for oil mixed and emulsified in concrete. The emulsion takes place after the oil is 
mixed with the wet concrete and not before, as has been done in a patented article. 

\ mere casual glance at the uses of Portland cement concrete would indicate that 
oils mixed with the concrete would prove very desirable for dustless waterproof floors 
for office buildings, for slaughter-house non-absorbent floors, impervious concrete drain 
tile and sewers. If the experiments to be carried on in the future prove that mineral 
oils in the course of time are not disadvantageous, the drain tile problem has been 
solved, for there can be no action of the alkalies or other injurious elements to non- 
absorbent, dense and impervious concrete. 

Such concrete will be particularlv desirable for silos. Some of the acids formed 
by the silage in the bottom of the silo would probably not attack a dense, non- 
absorbent, impervious concrete. 

Contraction cracks will be eliminated in cisterns, drinking troughs, live stock 
feeding floors and platforms. Some objection may be raised to the use of oil-m.xed 
concrete from the standpoint of its liability to flavour the water or the food. If we 
stop to consider that the oil is divided into minute globules, thoroughly emulsified, 
we will see that, while there mav be some odour, there is not likely to be any taste 
after the drinking trough, feeding floor or cistern has been in use for a ew days. 

Such oil-mixed concrete will be effective for liquid manure cisterns for the reason 
above described. It will also be particularly adapted to terrazzo floors; the great 



OtLS MIXED WITH COXCRHTJ-:. 



objc'cliiin .11 prcsciit l)fin;.j due lo contrriclion crarUs. A \\ hili- oil may be nii.\<-d with 
Porllaiul crincnt, while san<l and waUT ami ii-iixi fur the purpose of seltiiif^j brick and 
stone; it beinjj^ iion-eva|K)rative and non-absorbent no ellloresccnce or stains can occur. 
In fact sucli concrete can lie used in any \vorl< not requirinj^ extraordinary compression 
str<>n>;lli, and in wliicb tlie concrete docs not come in contact with heat. 

Ont' of tlie particular advantages will be for stucco work .ind exterior plasters. 
It would seem lli.il this idea of mixinij oil with wet niorlar was novel and new, 
but, like niaM\ discoveries, it only proves lo be a rediscovery. In the lirst century 
.\.i)., Marcus \ ilruvius I'ollio, the f.imous Rom.m architect, gives the following 
det.iiled spicillealioii for stucco : " .\ mixture of well hydrated lime, marble dust and 
white sand mixed with water, lo which mixture is added either host's lard, curdh-d 
milk or blood." In .\.n. 1280 at Rockin!,di.im C";istle, England, melled wax was 
mixed with the mortar. In a.d. 13J4 in ibe work of Kinjr Edward II. at VVestminsler 
pilch was mixt^ with morl.ir. 

The permanency of ihe Kom.an stuccoes may be partially accountc'd for by the 
use of oil mixed with morl.ir. .\lihouj.jh X'ilruvius used hotf's lard, .in animal oil, the 
mortars have withstood the action of the centuries, and in pl;ices where freezing 
tem|K>rature occurs in winler .uid 5j;reat heal in summer. However, the bote's l.ird 
must have been very Ihoroufjfhly emulsified by Ihe action of the hydrated lime. Porlland 
cement was unknown ;it th.il lime. 

In this connection the .-lutlior would like lo su.i,'tjesl the followinij specification 
for stucco, the third or finish coat :- - 

One part I'oriland cement, 20 per cent, (volume of cement) of hvdr.ilt-d lime, 3 
parts coarse white sand. l'"irst dry mix the sand and cement, ;ind with this mix drv 
hydrated lime, turnint;' c.ich three times with shovels, rako while shovellinsj. .\dd 
w.iter, turnini;; and rakiiii^ until Ihe desired consistency is obl.iined. Then add 15 lo 
20 [XM' cent, of white oil pelrole, ihe oil lo be by weitfht in percentaffe lo the weiyht 
of the cement. .V ijallon of oil pelrole weitjhs yh lb. .Vpply this mortar while the 
scratch coat is damp and as soon as scratch coat is firm enough fo stand the pressure 
or plaslerins:. If it.be desirable lo lint the stucco, colour the oil with any limeproof 
colouring matter, in proportion which by experimenl wilh sm;ill s.imples is necess.irv 
to i;ive the desired tint. 

.\ while non-volalile mineral oil is suggested for stucco and for mortar lo be used 
in selling while marble or light coloured brick, on account of the colour |x)ssibilities. 
l-"or concrete ubere the colour is not essenti.'il Ihe heavy black bituminous oils lo the 
light non-volalile pelroleum oils are successful. They are cheap and llieir name is 
legion. 

Do not use oils containing organic matter, and positively avoid, ;it least for the 
present and until further exijeriments h.ive l)een made, vegetable or animal oils, as 
thev are liable to form an .-icid which in turn may disintegrate the concrete. 

l.ime, sand and .inimal oils have stood the test of centuries. Portland cement 
and animal oils have not yet Ii.kI lliis opportunity. Il is within the range of possibility 
that the test of time may prove contrary to the theory, and animal oils emulsified 
be found not dangerous ; we will then consider a remark made by a very noted chemist : 
" If theorv conflicts wilh Ihe fact, we will have to cliangp the fact." 



169 



NEW AMERICAN CEMENT WORKS. [CONCRETE] 



s^^ ^-^n-f ' -^.. ^. MACHINERY AT | 

r 



;" ' ; -^ / NEW AMERICAN CEMENT 'f^ 

Pi^.^ -/S| WORKS I 



^/lWri| WORKS 



The account ivhich 'U'e are publishing in this article of the netu plant for the Altoona 
Portland Cement Co. should pro^e of interest to our readers, gi'ving, as it does, particulars 
of the 'various machinery employed in the operation of these ivorkst particular attention being 
de-voted to the Maxecon-KenI mills used for the purpose of ra'w qrinding. — ED. 



OwiNc. to the i^reat necessity for reducing" nianufacturiiifj expenses in the cement 
iinlLi^ir\, under the present market conditions, the following description of one of 
the latest American works may prove of interest to our readers, although it must be 
liurnc in mind that sonic of the new arrantjements would not be applicable in this 
country. 

This new plant, which was started in operation early in May, 1909, belong's to the 
Altoona Portland Cement Co., and is located about five miles north of -Mtoona, in 
Kansas, and comprises 440 acres, containing raw material, and 8,000 acres of gas 
leases. The mill proper is designed for five 8x 125-ft. kilns, with a rated capacity of 
3,000 barrels of cement per day. The foundations and walls of all the buildings are of 




!!• iH! 




^ 



A7-:ir AMHRICAN CEMEST WORKS. 



concrfli-, tlic culuiniis and roof trusses of slcfl, ami ihc rouls of tlic i[nlividiial build- 
ings arc ici\(rcd wilh asbestos rooliiijjf. 

The quarry is located a short distance north of the plant about 170 ft. above the 
raihiiad, and contains iqo acres of limestone and about 100 acres of ),'unibo soil from 
the llood plain of the Xcrdig-ris Valley. The natural elevation of the qu.arry jx'rmits 
the use of the ijravily system, which maUes it jxissible to brinj,' the roeU to the mill 
at a low R},nn-e. Ek'ctric air drills are employed, and the rocU is broug-ht by auto- 
malically dumpinij cars to a larf,'e giratory crusher, driven by a 50 h.p. electric motor, 
the cin|iiy c.irs beintj returned to the quarry by the weijj^ht of the loaded cars. 



>^-*fl 




Drver, Showi; 



The gumbo is procured by an overhead cableway and a steel dump scoop operated 
from the hoisting tower, .and is thus automatically dumped .and fed to a clav pulveriser 
operated by a 35 h.p. motor, while the power equipment for handling the gumbo 
consists of a 50 h.p. three-i)hasc motor ilriving a three-drum hoist. 

The rock when crushed to 2A-in. ring is further reduced by two hammer mills 
(each driven by a 50 h.p. motor) and fed to two rotary driers, while the gumbo from 
the clay pulverizer passes another rotary drier, both operations being oljtained by 
gravity. The driers are 6x60 ft., and individually operated by 15 h.p. variable speed 
motors. The driers discharge the rock and clay respectively on to two i.S-in. belt 
conveyors, transferring the dried material into the raw storage bins, which are con- 
structed of reinforced concrete, with a capacity to supply the mill for four d.iys. From 
these bins the raw material is brought into steel storage bins feeding automatic 
weighing and mixing apparatus, and from these to the bins above the raw material 
grinding mills. 



NEW AMERICAN CEMENT WORKS. 



[a )NCBETEJ 



•n , „„...-i;,.n wiili lir ■,iM>aratnrs are employed for the 

FiL'ht Maxecon-Keiit niill> in c.nnrclioii Willi ,iu >ii'"'' j u 

purp^:' of raw grinding, each mi,. U-in, driv,., individually by a geared 3a h.p. 

.constant speed induction motor. ,,,H-knnwn Kent grinding 

This mill, which is shown in /-i.i;,s. .;-,. is l>.i-t<i on 




Fig 3. R^w Mill, sh.iw 



■ r, ,-;„,,■ ind three rolls supported against the 
system, having a free "^^f\^;;:^'"^^^;':^-^:%,,J!oi approximately 
i.ifpi-ior surface of the grinding nng, witn an aujusiciu.c 1^ 



E 



NEW AMBRICAN CEMENT WORKS. 



on any sljuiii;' liinlior foiindalioii, ;in<! pracdcally run without the noise generally 
iiK'idenlal to trii.sliijifi aiul ijrirKliiis^ wurk. Hg- 6 shows the accessibility to the 
grinding parts. VV'hcllier the gear drive by electric motor is an advantage might 
seem doubtful, yet it is interesting that in this entire works only a single belt-driven 
machine is erected — viz., the aljove-mentionod giratorv crusher. Kent and Maxecon 
mills, bell-driven by elcclric nioU'rs, h.ive liccn, hunt ver, frctjiicnllv ii>ed in .\meric.T 




as well as here, and there is no doubt that, wherever electricity c;ui be had or produced 
at a reasonable figure per unit, it is the ideal power to drive this kind of plant, because 
It makes each individual grinding aggregate entirely independent of the other. 

The method of mixed fine and rough grinding and air separation is used in this 
Iil.mt, which insures a thorough mixture and uniformity of product. The fine product 
cummg from the separators is brought by screw conveyors to steel supply bins over the 



NEW AMERICAN CEMENT WORKS. 



[OQJNCBETEJ 



kilns, while the coarse tailings go by gravity back into the n,iUs. These fine bins have 
a capacity of ten hours' supply to the kilns. ■ ■ ,, 

■ Sepamted from the raw grinding department is the k,hi room contammg three 
Sx I- ft rotarv kilns, with ample space on each side for the erection of two additional 
kilns".^ Each kiln is driven individually by a 25 h.p. variable speed motor, geared to the 

driving gears of the kilns. , • , ,1 u ^ 

The fuel is natural gas. The kilns discharge into a pit from which the hot 

clinker is transported bv an electric travelling crane carrying a clamshell bucket, 

distributing the clinker 'in the storage room. This electric crane is also used for 




transporting the seasoned and cooled clinker to the supply bin erected over a hammer 
mill, which onlv crushes the large pieces of clinker to about .-in. ring. 1 he 
Maxecon mills, which are also used for the clinker grinding, will take however, the 
clinker up to i-in. ring. At thi. point the proper amount of gy,>sum is added by means 
of an automaticallv operating weighing and dumping device. 

The clinker-grinding department is an exact duplicate of the raw material grmding 
plant also containing eight Maxecon-Kent mills operating in conjunction with air 
separators, each mill being driven individually by a ^2 h.p. geared motor. 

From the finishing mill the cement is conveyed to elevators which feed into iS-in. 
belt convevors, from\vhkh the finished cement is distributed into three separate 
storage bins having a total capacity of 120,000 barrels. These storage bins are also 
constructed of reinforced concrete, steel trusses and columns support the roof, which is 
covered with asbestos roofing laid on if-in. yellow pine tongue and groove sheeting. 
From the stock bins the finished cement is conveyed by 14-m. screw conveyors to the 

17 + 



I J. tiONyrUIKTlOJAlJ 
tv LN<UNt.l:JflN>. -~1 



NEW AMERICAN CEMENT WOk'KS 



sacking- rocim, fic(liii)j; tho bins of tin- aLilniiialic pacUt-i-,. Vhv shipping niuiii covers an 
area 60x75 ft., offering; ample room for eonvenient working and also storage for 
sacked cement. 

.Vtlenliiin i- called In .a lew original features ul this mill, llu- must iiutewortliy of 
which is Ih.il thi' raw m.ilerial storage bins, raw grinding mill, kiln room, clinker 
storage, fmishing mill, stock house and sacking room are all in one building enlircdv 




connected, of concrete steel and under one roof, making this main building 820 ft. long 
and 75 ft. wide. The steel bins in the raw and fmishing mills are directly supported by 
the columns supporting the roof trusses. By following this design considerable saving 
was effected in building material and cost of erection. 

-All the machinery is driven individually by motors connected direct or geared in 
order to obtain the necessary speed ; this means that belt drives, pulleys and line shafting 
do not exist, whereby a considerable saving in repairs and cost of maintenance is 
claimed to be obtained. The mill is, .according to the Ccmciil Record, one of the ir.ost 



NEW AMERICAN CEMENT WORKS. 



(mNCBETI 




176 



tft. ENr.lNEEJ;iNC.~-J 



NEW AMERICAN CEMEXT^WORKS. 



r.iiilLin and IrM (^Liiijpixi cenu-iil iiiilk in Amcrici. and (nviiij,-^ lo ilu- results alrt-id) 
ihlained, another iarfje cement works on very similar lines is in course of construction, 




rir,. s. Ki, Ks. c'l 




I-u;. 9. Kiln Drives, Motor geared to Kiln Gear Base. 
whieh will be, however, of a much larger capacitv, with 32 Ma.xecon-Kent mills f,,r raw 
material and clinker. 



177 



TESTS. 



iCDNCBETE] 




TESTS ON REINFORCED 

CONCRETE CONDUCTED 

IN GREAT BRITAIN. 

(PART VI.) 



The first fiue articles of this series appeArea in our May, Sep-ember, Noi'en 
and February numbers respectively. The folloti'irn] particulars of tests are no' 
and further articles 'null appear from time to time. — ED. 



nted. 



TESTS FOR H.M. OFFICE OF WORKS. 

A NU.MBER of test? were conducted upon plain and reinforced concrete columns and beams for 
H.M. Office of Works, under the direction of Sir Henry Tanner, in connection with the extension of 
the General Post Office, constructed on the Hennebique system. It will be seen that the tests range 
over a considerable period. 

We also record in the same connection some tests on plain concrete cubes so as to provide 
some idea of the resistance of the concrete. The steel was ordinary mild steel, passing, the ordinary 
specification of 28 to 32 tons tensile strength per sq. in. These tests were conducted bv Messrs. 
David Kirkaldy & Son, and we give in the following tables full details obtained from reports made 
by Messrs. Kirkaldy, and details of the composition as supplied by the Clerk of Works of the General 
Post Office Extension Works. 

We also giv.e below diagrams prepared by Mr. T. .\ubrey Watson, .A.M.Inst.C.E., who had charge of 
the work for Messrs. Holloway Bros., Ltd., the contractors, referring to four of these tests on columns, 
and based on the allocation of the distribution of stresses bv the elastic theorv. 










J^- 4iH -/ 




_ Ej^'I" ^ ',^:" : 


Wtt^i- z -- : 






{.''/i' 9 1 




h li j '^ " _i_ 






1 rr # ■- z ^1 " 


f^ ^P ^ 




"""• w i ■/ ' 


sL'i' ' 














1 ^ 















T 


J 1 1 J 


TI ' f 


l-l-U 


41-1- 


^3l>o' 








' ' 4 


M - 


- 


-- i 




'/ 




' ' \l 
















- S 


























W '/ 




\)f' 






- V - 


<?/ 










-- f ^ 


fV" 


_^i 




- 




E 








- 
















"-/ 






/AJ _ 


"tf^i "" 




~~ 


Ill 


_ 


^^ 








^+tr 


- 


n^ 




~^^ 




















A ' 






























r 


1 1 


; 




1 










1 










1 1 1 1 


ill 


1 1 1 







/^efor/TTof/ff/r ^e/- i/zr// U/ra//^ 



fy. ctiN.viuiK-riaNAl.l 



TESTS. 



!|Sggg|gggg = 



|„8^|„|„|, 

? I I I I 

I" I I I I 



■tw- 



! ■Ss~gSglc E^i-. ix'^ !Z S. i. iZ s. 

5S.S = HiiE5S'gt!S''Si-SS; g S £ S £ 



'79 



TESTS. 









^ . ,^ . .^ . ^^ . .^ . .^ . 


















is 


. s 


.J^ 


•g o-^iS o"ij o "5 o~"5 c -:.'o o^ 






rc^itsOSfflOtf; cgOSrtC'SreO'iJ 


■c 


^ o 






un-CwtN.OwCCti'J-CiZNCCr-.Cl 


a> 








^cc£'^wi'"'^o"°"^'°"'-"^"'^° 




"c is 






>.C> >. 'n^t-.o'-' >.. c'" ^.P,"" >.o'*' 


C- 


1: X 


i 


£ "a's " v^^^a" ta "^a " ?, 


t; 






; ~^ ,jr. (T — M t/i •-■ CO '-^ -^ 00 "■ -^ IS. '■/■• — t>. 


C 


^ 






.- re ~-^i.r « — ;r cs =i-:r « ^-r « -—-■" « •-' 










^ -> > > > ^ 


h 


m 








^ 








M tN. ". 




'^ 




^^ 


-: t 5 


£ 








c ^ , , 














* 


1 


u 


S -, -- r. :c f ^ 


5 


u: 


55 


- 


^ h ^ t z 2 


j3 


























•N ^c - -r <K c- 




^ 7. 






t^ u- a; r »^ C^ 




■-5 


i ~ 


£ '^ ^' -^^ '^. =. =:■ 


c 










W 


H f 


"^ 












3 C = C = C 




0(2 






,. =-^C>nC CI^OoO„ 










^- c » c «=- ^. '^. ^ 'I ;r ".| ^ ;^ 




< S 






= C -T-OCOiCvON<^o'£''.r 









w ^^«-r.-.-c^■- (s.'^'C^ 


c 








M M rj n M « 
























^c 




£ 


^ r^ 


f* 










s 






















-JO, 


















- 








c c c c 










: ^ ^ £ I 1 










r r r r ' ' 




c i^ 




f^' 




■"■ 


Id <-3 








^ 


y £-' 






;"" T- 1^ ^ 1 1 










.- r ? r 1 




E 8 ^ 


■^ 


- 






(b :^J 


z 




■5 


o z-; 


-C 


a 


30 -^ «~. -a o o 


^ 








u-i U-- U-, u-i O -C 










?????? 






g" 


- 




u. t; 








2 la 


G. 


-* 


f f ? ? f f 


o"i 


►J gc" 


Q 






t s 








< < 










U 55 


5 


t 


^ t ? ? F 1 


4^ 


Z ^:S 


£ 






r.'< 






^ 


Id :- 


■= 




:; ?. i ,^ ^ =; 




^H 


1 






51 


= 


.^, - ^ -1 C 'C 


Z ;; 






? ? ? V V ? 


^d 


t- 




^ 




- M 


£ - 






1 


C c 


5?, - 






1 r^ »-, fv U-, -^ :c 


— " 


< u 






1 3 5 5 5 c c 


C " 






















*- ~ 








fl 


^ k' 






T y. - 00 r^ o 














t/i ^ 






; ^ ? P P ? 


', ^ 


=?; !3 




— 




(.; ^ 






;. 2 


= r - 7 ; J ? 


51 


< ^ 




S< 


T : : i ^ z z 


£ g 












~ u 




- 


^ ^ -- c « » 


Si 








.^ .^, c c rv o 










= •, ;, -■, ;^ ;, ;, 




v'-J 




r 


<: .i fi ^ ^l ti 


'err 












> 






1 ■>-- '- JT'SC ■- - s^ ^ '-^ 


_^ .y. 


a 






g^: : ^ -- .i-|.S-- ^ ^ ^ - ^ ^ 


= C 








u r - z = :. -----S^c c c c c a. a 










1 ^iZ-:--z^;.«S— *- *^ --^ — ■" 










1 -^--'~---'^o>: X X >^ >•■ « 




-V. g 




1 


"■g|t ^-^ '.l=S B B 5 S 5 5 


1- 






P 


1 e ■^ ^ w ^- . - ^ s- -^ -^ " -; r^ -; 


= < 








0^ 


















^ -- . . — ^ en u _ in o --*- in ^ ^ ^^ ,^^ ^^ ^ 


II 
















1 - . ^ _ u- 
























■^ ^ 






'2; i £ : £ S S 




1; 








""^ 



iSo 



THsrs. 



rt 



•tiitdj i 






S 5 _-" 8. a: ' 






■fi ° 






lilf II 



Z^t 






5 s: 1 1 -rl-i- 






TESTS, 



ICDNCREJE] 



- 2-3 ^in 0! 





^ __ 


_.._ „-,..•„ , 




j: u 4i rt £ 2 ^i ^ 




X 




§^|1 £|§«m|eI"°e|.^ 


i 


"■sllisli-l? 


|lll ■ pllllllllll 




-^ '- '1 


- r^ 




















p i 


II II 


II 11 








g'^ 


^ r^ ri 


^ -? 




-' 


- 




q 




,, 


- 


- 






J- 




~ 




c 


J 


% ^. 


7, .7 




" 






c" 


$ 


t~^ - 




















ta 








Q 


g 




~ Trr. 










•o 


" 
























.»_ 


~ r 


r r 


















^ i^ 












i; 





" 


" 


X 


; 


r^- ic 


"- 




i 


r-^ ?x 


? ? ■■^- 














d 


" " 




•X 






c 


3-36' 3-6o- 


3M5' VS-'" 














- 


i ?-iv4""'r; S'3'**"v 


ri3-52".;; ^i3-62"? 














'^ 


.V34' '.-.in" 


3-30" 3-4Q' 




. . / — ^- — 


__ _ 






















~ C ^ 


z; ^ 




^^■ 


>■ 




c.>- 




n 


«, 




1 




J5 


«^ 








— 1 


-\ 








^ 


— f- 








— 1 




































= i 




■ ; 






















J 








































-^^ 




■1 










j 








>.«'^ 




:.-.! 






























































■_>. c r^ 




















b! 


III '^ 




;;! 


». 




1^ 




1 


», 


J 






















tl 


G 






-i 






, 




















































c 5 ^ 




■^i 














■J *^ 






















> 1 




h S s 




" "i 


















||J 




"-i 














X '■ 




"i5| 1 1 




"St 






^ 


--J 


1^^ 






1 






















5? 1 






''¥Ji 




1 <r 


!l » 




^S 


^ 


c t-. 


00 c^ 








fiz 


&: ^ z. 


" " 



TESTS. 



Kii.ixr> 


.,f 1..X1I i(.Mi:srs IIV 1). KCKK*[.l>V ii Si.s. TO 


.\SCF.RTA 


IS Till 


RliSISTA.NC 


TO TllRUSTI.NO 


SiRtSS 


OP Eighteen 




ur C.JNCKUTii, RECElvin i-tK Mk. |-. Wood 


WARI), C 


KRK . 


1' Works, I 


.IM KAL I'OST OFIKI: K ,\Tt NSIO.V. 












liase 
Area 


Crushed 1 


T«'St 
No. 


Description 


Weight 


Di 


nensions 


1 




Per 


Per 














Stress 


sq. in. 


sq. It. 




Composition : l yd. crushed Thames ballast 


lb. 




in. 


sq. in. 


lb. 


lb. 


tons 




to pass I' mesh, J yd. Thames sand, 


















7 cwls. cement 
















I'P 


Aee nearly 2 months (7 weeks, j d.ivs) 
















57.M* 


M.irked n 


5-f>5 


4'Ot) 


398 X 404 


1 5-08 


.3".875 


1,920 


■21-5 1 


57 U* 


M.irkt<l I), Oct. 25th, 1907 


561 


4-01 


398 X 402 


ifi'OO 


29,075 


:8i7 


116-8 1,4-4 


571-* 


M.irke.l 1). Oct. 25th, 1907 


5-67 


4-04 


4-oox 3-98 


15-92 


25,500 


1,602 




57 17* 


.\l.irke<l W. 


5-44 


4'00 


390 X 3-98 


15-52 


33.25-T 


2,142 


■ 37-7 1 


57.!5* 


Marked \V 


5-57 


4-00 


398 x 3-94 


15-68 


31,650 


2,018 


129-8 - lio-6 


57.!<i* 


M.irk.ti VV 


5-6o 


4-02 


3-94 X 400 


■ 5-76 


30.475 


1.934 


124-4 1 


y« 


Agv 6 months- 
















t7Mt 


Marked l>. Oct. 25th, 1907 


5-22 


4*oo 


4-oox 3-97 


15-88 


59.900 


3,772 


242-6) 


■ 7nt 


M.irked O. Oct. 25th, 1907 


.5:7 


4-03 


4niX4-oo 


16-04 


56,650 


3.5 12 


227-1 .1 229-2 


I7«t 


M.irk.il I). Oct, 25th, 1907 


5-36 


4*04 


4-02X4-0I 


16-12 


54,600 


3,387 


2,7-8 1 


■ 7.1(>t 


.M.irk.d VV. Oct. 2^th, 1907 ., 


5-26 


3-93 


405 X 4-OI 


16-24 


53,5«o 


3.294 




1 7.17* 


Marked W. Oct. :5lh, 1907 


5-24 


y<>5 


407 X 4-02 


16-36 


51,000 


3.I17 


200-4 ■ 203-7 


■ 7l8t 


M.irked W. Oct. 2'5lh, 1507 .. 


5'2o 


3-95 


400X4-00 


16-00 


49.150 


3.091 


198-S 


KR 


AKf iS months— 
















i8i8; 


Mark.-d I) 


5-4 ■ 


4*or 


405 X 401 


16-24 


68,640 


4.227 


271-8) 


i8;n: 


Marke<l D 


5-40 


4*OI 


4-03 X 399 


16-08 


67,440 


4.191 


269-7 r 268-0 


iSl'i: 


Marked l> 


5' 24 


4*oo 


3-99 X 3-9'> 


15-80 


64, 5W 


4.082 


262-5 1 




Marked \\' .... 


5*12 


V97 


4-"4 X 3-92 


15-84 


54.960 


3.470 


2-'V2 ( 


l8;i; 


M.irk.-.l U .... 


5-0 


4*1 1 


V99X vu« 


15-88 


U.:"i< 


1.291 




l8s.it 


Marked W .... 


,5-27 


,(•04 


4-04 X 396 


.5-84 


,l'l.68.i 


3.M') 


l'.;:'; >'"■' 



Note. — Cubt-s mar 
Riport No. 3, dalcd Dvr 



Hearing surfaces prcpart'd irm*. 

I'll " D " ivtTc mixed fairly dr>*. Cubes inarkec! " \V " 

18th, 1007. t Report :No 

X Report \o. tS. f!it.d M;iv -.r I. i.j,.^ 




TESTS. 



ICQTMCBETEJ 



Thrusting Sirfss of Six 



ARD, Clerk op Works, Geni ral Post Of 

















Crushf.l 


T«t 




Description 


W.iKht 


Dimensions 


Base 
Area 
























Stress 


Pit 
sq. m. 


sq. ft. 








lb. 


in. 


sq. in. lb. 


lb. 


tons 




Composition : 


I vd. cmshed Thames ballast 
















to pass r 


mesh, i vd. Thames sand. 
















7 cwt. ceiT 


ent 














«Q 
























4::-26 


8-00 7-85XS-00 


62-80 


219,500 


5.495 


224-8) 




Ditto. 




42-63 


8-02 7-85x8-00 


62-80 '205,000 


3.:S4 


205-9 -212-0 


1214* 


Ditto. 
Composition : 


1 1 yd.'Tham'e's sand,' 7 cwt'. 


42-17 


8-02 7-84 X 8-00 


62-72 


196,300 


3,130 


201-3 » 


27zqt 


Age J months 




38-98 


8-03 8-01 X 7-92 


63-44 


141,500 


2,230 


14,3-4 ) 




Ditto. 




.38-11 


8-03 8-05 X 7-90 


53-50 141.900 


2,231 


14,-5 -144-0 


27Ut 


Ditto 




39-.35 


8-07 8-01x7-96 


63-76 ,144-000 




145-2 > 



Rr-porl .No. 4. d.it..| M.ir. .> = lh. 



Bearins surfaces prepared true. 



R.port No. K. cKit.-d July 14th, l-joS. 







E^^P 


sn 


>^.r-i- 


\m 




'^kVisSSI 


i 






ppfs 




. \ 


1 


■ ^ 


if ■ ■ 


mk 






1 " 




f~—i 


wjL 




■'•<. 


1 14 

1. "*■■■'■'' 


r.^j.;~*--.. • 


' t 


i *■ 




■ 


1 

1 / 
I ' 


J 


' 1 


" 1 


K> ' ' 


( 




' 





■ 






B 1 '■ ,f 




' 


i- \ 




|h^v '*^ 


1 ;^ 


l^m 


i^£U^:^i,, M 






■ w. ^.^I^Wjwr-pHp 


^^fljpff^^.«^-'-'- ^J 


! ^^ 




' ^ JHyj^^^HuuMM 


aBiplHH^^^S 



. lesitd lur the new General Post Oifice,) 



18 + 



M 



CONVRRT/Xa A STEEL BRIDGE. 




SOME RECENT WORKS IN 
REINFORCED CONCRETE 
IN THE UNITED STATES. 



The parlicu.ars In this jrlicle show some Interesting neiv -works In reinforced concrete 
■which hjve recently teen cotnpleleJ In llie United Stales. The description of the Pennsyl- 
■ojnlj Flltrjilon Pljnt Is ■worthy of speciM attention, js it shows ho-!u reinforced concrete 
can be effective^ applied to this class of -work. — ED. 



CONVERTING A STEEL BRIDGE INTO A REINFORCED CONCRETE 
BRIDGE. 

Till-. Coiinly fdinmis.sioners, the govtrning board of public allairs, of Cowley 
County. Kansas, have for several years been building stone and concrete bridges 
exclusively. 

The bridije described in this .article w.is a sm.ill steel s|>an, with 28 ft. of wood 
trestle .-ipproacli, .and was ,in uncompleted link in a chain of (KTUianent struclures 
between the town of Kock .unl Winlield, the countv seat. 




REINFORCED CONCRETE. 



[CDNCRETEJ 



Messrs. Hughes &■ Hnmiiiond, engineers of Kansas city, were requested to make 
an examination of this structure to see if some means could not be devised to put 
a concrete floor on the steel span and a concrete approach span on the end. 

On examination it was discovered that the steel members were too light to carry 
the increased livid from a concrete floor, and, ns no wav to reinforce the same seemed 




Tf.420 



practicable, except that it be used as a nucleus for a concrete girder, this was 
suggested to the Commissioners, and, as it met with their approval, the design was 
made, and, on account of the unusual features of the work, contract was taken on 
cost, plus lo per cent, for tools and engineering expense. 

i86 



E 



CONVERTING A STEKI. HRIDGE. 



OiiL- iHW masonry abutment was constructed on the approach end, and others 
were repointed and repaired. Forms were constructed, encasinjj the entire steel bridj,'e 
and approach as seen in ilkistration on paj^e iSS. 

I'he structure had to be taken down and all sttH'l work was cleaned of rust, .uid, 
after abutments and piers were repaired, was re-erected and the additional reinforce- 
ment placed and carefully wired in position. The forms were constructed of i-in. 
dressed sidin^js and 2-in. x 4-in. ,ind 2-in. x f)-in. braces throuj,'h, so as to prevent 
bulginj^, due to weight of wet concrete. The mixture was made very wet, what is 
generally designated as " sloppy " so that it would pour easily, and was thoroughly 
tamped. When forms were removed the surface showed no pockets, which is so 




— ELEVATIOM- 





H .-CAeP.P. 






T 


~ 


r r r 




^-iW- 


>r^ 


^^, ^...^ 


Xi^L- 




aS'-O" GIRDER, ■ 




IMSIDS ELEVATIOW -^ nALFSECTI « 



General elevations and detail sections. 
Reinforcld Concrete Bridge in Kansas. 

lere the concrete is mi.xed too dry and care was not taken 
to tamp and cut the outside ne.\t forms to permit the concrete to flush and fill all 
voids. 



noticeable on work 



The cost for this bridge was about two-thirds of the cost for a new concrete 
structure having the same dimensions, which are a 50-ft. bridge span, an approach of 
2S ft. 9 in., and a road bed 14 ft. wide. 



187 



REINFORCED CONCRETE. 



[CDNCBETEl 



REINFORCED CONCRETE ON THE BOSTON ELEVATED RAILWAY. 

The Forest Hill extension of the Boston Elevated Railway, which has recently 
been completed, presents some unusual features of treatment, and reveals something 
of the possibilities of concrete for concealing- the customary unsightly features of this 
class of construction. 

For most of its length of over two miles this extension follows in general the 
ordinary type of steel elevated structure. Where, however, it crosses the .^rborway, a 
broad boulevard and parkway, a treatment more in conformity with the nature of 
the surroundings was demanded. This led to the construction of a section ^72 ft. 
long, of the peculiar type here illustrated and described. 




This section gives the appearance of girder spans of concrete masonry resting on 
centre piers of concrete — a design unique in elevated railway construction. This 
result has been effected by a radical modification of the columns and transverse girders 
and by enclosing all of the steel work with reinforced concrete relieved by exterior 
mouldings and provided with a solid ballasted floor between sidewalks protected by 
piirapet \yalls. 

The -Xrborway spans are alternately 45 ft. and 64 ft. long, and are supported 
by column-like piers in the centre line of the viaduct. These piers carry double 
cantilever transverse girders which support the tracks. 

The essential construction of the pier is a rectangular steel tower with a transverse 
base sufficient to provide a satisfactory moment of stability under the eccentric, 
unbalanced train loads it supports. The towers, 20 ft. high, have a rectangular base 
5 ft. 7 in. wide, and 8 ft. 8 in. long over all, transverse to the axis of the viaduct. This 
base is made with two separate 2-ft. S-in. x 5-ft. 7-in. pedestals, each of which receives 
two vertical columns and is anchored by four i|-in. bolts. 

The structural steel is entirely enclosed in solid concrete of a minimum thickness 
of 3 in., reinforced with rods -J- in. in diameter and ui)wards to strengthen it and 



188 



^ 



CDNyrcuc-rioNAi I 

E3S01]VMiJ<lNri ^ 



liOSrOX ELEVATHD RAILWAY 



.■Miclior il 1(1 ilu' sUtI UDiU. I Ik- Idwit flang;os ol' llic longiludiiial jjirder.-, are 
coiitKcictI ill ilic outside panels by a horizontal concrete ceilinj,' 3 In. thick ; in the 
fi-iitre panil ihc ceilinf,' slal) is considerably depressed at the piers and slightly curved 



ypc cf sieel flevatt'd str 



I 





1 of station snJ Arbor way— rails enclosed by concrete t 
Boston Elevated Railway 



1S9 



REINFORCED CONCRETE. 



[CQNOaJEj 



in longitudinal section to make a false arch soffit conforniabU 
of an imitation solid masonry structure. 



to tin. 



al d<'sitrn 



TtiL- top flan£ 



; of the longitudinal t^irdii- ^u]<]> 



ous reinforced concrete 




::;t g: -of he ou^idVlon,^itudinal girders by a continuous longitudinal concav^ 
Concrete fascia slab 3 in. thick, which is quadrant sha,>e m cross sect.on and really 
forms a deep cornice moulding under the sidewalk. 
190 



^ 



, CONM UIICTION' 
EN(.INLt,BlN<i 



a 



PITTSBURG FILTRATION PLANT. 



Al the piirs the concrete construction is rallier coniplicatiil owinji to the elaborate 
cliaracter of the {girders, diaphragms, and other members connected (here, and to ihe 
provision for lonj^itiidinal movement at tlie expansion joints. The four columns of 
each pier are enclostd in an octaj^onal mass of corurcie S ft. 4 in. in diameter, whicli 
forms a shaft. 

.\lthoui;h the pier concrete possesses considerable slren^jlh as .1 column it is not 
desifjnetl to c.irry an) verticil load except its own weijfht, and has neither reinforce- 
ment bars nor anchoraK^' except as it is interlocked with the (lan.i,'es of the ste<-l 
columns. The concrete extends from the j4;rouiul to the lower ILinyes of the Ir.ins- 
versc girders, and the slij.c'T'>-L>atterwl faces are relieved by a base course protected 
l)\ reinforced concrete fenders at the angles and by rectangular mouldings at the 
top, where it joins the false arch solllt and the concave surfaces enclosing the Unee- 
lir.accs. 

Temperature mnveMiijils are provided for at each pier by o|x;n transverse- 
expansion joints with a normal clearness of i in. through the concrete floor. The 
sidewalks, 3 ft. wide, have rein forced-concrete curbs. The space between each of them 
and the lloorslab is utiliscil liy Iwclvf rcclangidir conduits for electric wires. 

CONCRETE FOR THE PITTSBURG FILTRATION PLANT. 

Concrete is being used almost exclusively in the construction of the new Pittsburg 
Mltration Plant at .Aspinwall, Pennsylv.ania. Ten new filters, each covering an acre, 
are beinj^ added to Ihe old plant to supply the city of .Mleghany with filtered water, ihe 
floors, rsKif, roof columns, dividing walls between fillers, ;uid most of Ihe conduits 
being of concrete. 

The bottom and inside slopi's of the basin have a concrete lining b in. thick, and, 
for further protection against frost and wave, the inside slopes between high and 
low w.iler levels are provided with concrete revetment slabs 7 ft. square and 12 in. 
thick, l.iid upon a bed of gravel iS in. in depth. 




191 



REINFORCED CONCRETE. 



[CDMCBETEJ 



The filters and galleries are of the usual concrete construction with a groined arch 
roof supported on concrete piers, spaced 15 ft. centre to centre, the whole being covered 
with ^, ft. of soil for protection during cold weather. 

General view, showing floor, columns anfl roof. 




On this page we give a general view of the work, showing floor, dividing walls, 
columns and roof, all of which are of concrete. The movable cableway used to convey 
the concrete is also seen. 



[g 



PITTSBURG I- 1 LT RATIOS PLANT. 



'riurc :iic l<>rl\-six lillcrs in all, wilh a net area of one acre each. The filters are 
163 ft. X 26j ft. in plan .and ij ft. hi>,'h between floor and roof, which is supported 
h\ 170 concrete |)!ers, c.ich jj in. square. 




Visw of concrete intake condu 
Pittsburg Filtration Plan 



The under drainage system consists of a concrete main collector upon the floor 
of the middle bay and extending the entire leng-th of the filter. 

The water, which contains at times large quantities of silt .and is often highly 



■93 



REINFORCED CONCRETE. 



[CQNCBETEJ 



polluted, first enters a concrete intake on the river l^anli near tlie pumping station. 
I'Voni tliis point it passes through a concrete suction conduit 124 in. in di.inieter. 

Mr. Morris Knowles, Chief Engineer of the Pittsburg Filtration Works, had 
charge of this work, and the progress made on the job is remarkable, and it is 
expected that the conir.ict will be finished long before the date set for completion. 

IMMENSE CONCRETE RETAINING WALL. 

The wall .and parapet on Third and Hope Streets, Los .\ngeles, a part of which we 
show in our illustration ,and which h;is just been completed for the city at a cost of 
$ig,ooo (/^r3,4oo), is a monument of concrete. The wall has a length of 600 ft. and 
is 52 fi. S in. high at maximum h<-ight, witli a minimum of 13 ft. 




The expanse of the wall is broken midway with a staircase of about 100 steps, 
w hicli complicated the construction. The wall is surmounted by a 5-ft. parapet. The 
foundation at maximum height of wall is 14 ft. wide; the wall ranges in width from 
8 ft. I in. to 3 ft. wide at the base of the parapet. U]3wards of 3,000 barrels of 
Portland cement were required in the construction. 

The s[)ecifications called for construction in 40-ft. sections, no two .adjoining 
sections to be constructed simultaneouslv. .Alternating expansion and con- 
traction joints are provided for. The section method of construction required 
frequent removal of the contractor's plant and two sets of workmen were 
employed, one for mixing and spreading concrete, the other on the forms and back- 
filling the wall with a 6-in. layer of coarse gravel. The concrete of one section 
was allowed to set before another section was begun. 

-\t the upper end, where the height is not so great, a wooden trough was used 
on account of the greater ease and quickness in moving it. .\t the lower end of the 



194 



CONCRETE RETAIN ISO WALL. 



w.ill. tt lure llio ;ij,'Kri'K'''tt' must be run j^realer (.lisi.inces, ihc concrtlc \v;i.s conveyed 
fii>ni ihe mixer throiij^Ii the iron piiK- and placed where needed in the forms bv a 
movable sliorl Iroii^h. In this manner the concrete was somelijiies conveyed loo ft. 
and more. It was carcliilly spread and lam|)ed. 

The expansion and coruraction joints alternate, a distance of So ft. cxistinj.; between 
two expansion joints or two contraction joints. The expansion joint is made bv nailing; 
shet^tin}.f across the <'nd of the section and properly bracinj.j the same. The exp.msion 
joints are reinforced with pilasters. 

The contraction joints were fornu-d midway between the pilasters by bringin.ti the 
end of one section of the wall up to a true vertical pl.uie at a riijht an,i;le with the 
central line of the wall. 

'i'he concrete of one section was allowed to set before the other section was be^jun, 
as noted, and the forms were demoved as soon as the concrete was set sufficiently to 
st.ind, and the exposed face of the wall w;is jjiven the proper amount of moisture and 
covered to a depth of J in. with a coat of pl.ister ooniixised of i part cement to \\ parts 
of clean, sharp sand. Before applyinjj the plaster coat the surface of the concrete was 
lhorou.i.jhly cleaned and covered with neat cement powder, the mortar coat bein^j 
.ipplied immediately after. .Ml exposed surfaces of the concrete, except that of the 
parai)et wall below the caps, were brouLfhl to a smooth surface by usini^ wooden floats. 
The surface coat of e.ach section required to be completed in one dav. 

EIGHT STORY REINFORCED CONCRETE BUILDING 
AT PORTLAND. MAINE. 

The ei<,fht-story building described in this article was recently erected at Portland, 
Maine, a reinforced concrete frame being used, with flat slab reinforced concrete floors 
.uul brick walls. These walls h.id a total thickness of 12 in., 4 in. being outside the 
reinforced concrete fr.ame and the remainder resting on the beams. The stairs through- 
out the building are of concrete, veneered with marble and terrazza. 

The columns we're mixed of unusually rich concrete — one part cement, half part 
sand and two of crushed stone. This gave a very hard concrete. Embedded in the 
columns are vertical steel b.irs. 'I'he ends of these are milled so as to give an even 
bearing from one to the other and aligned by the use of a short length of iron piix-. 
Around these are steel hoops, 2 in. by \ in. thick, lapped and secured by two I'-bolts ; 
and on the lower Umir there is a large cross section of steel, besides the concrete 
carrying the lo.ad. 

The columns in the basement and on the first fliKir have their reinforcement hoo|)ed 
togeiher, the hoops being spao?d 12 in. apart throughout the length of the columns. 
Those on tlie remaining floors are secured against flexure by bands encircling the 
reinforcement along the middle third of their length only. The tops of the columns 
ll.ire, and steel bars, which extend down the column inside the steel hoops, branch ofT 
from the columns and are joined together by horizontal hwips at the floor level. When 
the concrete is in pl.ace this arrangement of steel reinforcement ;,cts like a mushroom 
spread footing built upsieb down. Over these heads steel bars run three ways, so that 
every part of the floor sl.ib has a mat of steel .at the bottom carrying the weight to the 
columns. 

.\t the second floor level cast-iron saddles or spiders are used to make continuous 
the column reinforcing. The floor slabs are 7 in. thick for the first floor and 6 in. 
thick for floors above. Plaster is applied directly to the underside of these floors, this 
does away with lathing, and, as there are no beams, it saves in the total height of the 

'95 



REINFORCED CONCRETE. 



ICQNCBETEl 



buikli^^,^ For final floor surface, screeds be.ldino in cinder concrete rest on the floor 
slab, and across these is nailed the finish ILmh'. The electric light ducts and plumbing 




run under this wocden floor. There are two electric passenger lifts and a freight lift 
with entrance at the rear. 

We are Indebted to the Ccincnl Age for our illustrations of this building. 



f J, coN.M umrioNAi.l 



EIGHT STORY BUIUjING. 




I E S 



i Jl «^k 



iniai4.4B 




nforcenient for first flo 
K Building at Portl 



LIVERPOOL ARCHITECTURAL SOCIETY 



ICQNCBETEl 




RECENT VIEWS ON 
CONCRETE AND REIN- 
FORCED CONCRETE. 



SCIWE PAFEPS & DISCUSSIONS. 



// 15 our intention to publish the Papers ana Discussions presented before Technical 
Societies on matters relating to Concrete and Reinforced Concrete in a concise form, and 
in such a manner as to be easily available for reference purposes. 

The method tne are adopting^ of di'viding the subjects into sections, is, "we believe, a 
nenv departure. — ED. 

THE LIVERPOOL ARCHITECTURAL SOCIETY. 

REINFORCED CONCRETE AND STEEL FRAME 
BUILDINGS. 



By MR. F. E. G. BADGER. Depuly Cly Bmldmg Surveyor. Liverpool. 



Mr 



G. Badger read a paper on "Reinforced Concrete and Steel Frame Buildings" be/ore the 
Liverpool Architectural Society in November of last year. 

At the end of the lecture Mr. Badger showed some very interesting lantern slides illustrating some of the 
works of a few of the reinforced concrete specialist firms, and also went into the prices of certain steel 
frame buildings, giving diagrams of the extent of the buildings. 

The Lecturer be|jan by stating- that the Building Regulations in force in the principal 
towns in the L'nited Kingdom had been a great obstacle to the projjer development of 
this method of construction, but a reformation was quickly taking place, and many 
towns had followed in the footsteps of Liverpool and obtained Parliamentary powers 
to relax or modify the provisions of the buildin.g regulations. Formerly it must have 
been very annoying to architects to be comjielled to make the outside walls — which were 
merely acting as a curtain to keep out the weather, and which were not carrying any 
floor loads — of the full thickness of brickwork required by the schedule. This course 
involved not only an additional cost on the building owner, but in the case of a large 
building reduced the available floor space. 

Steel. — Considering first the mere material, it might be said that unless proper 
precautions were taken steel had two very undesirable characteristics : first, a loss of 
efl'ective area of metal due to oxidation, and second, complete inability to sustain 
itself when subjected to the temperature of ordinary fires. With regard to the first 
characteristic, there was practically no limit to the life of steel provided it was 
designed in such a way as to admit of thorough scraping and painting peri(xiicallv. 

\\'ith reference to the behaviour of steel when subjected to fire, most of them were 
familiar with the extraordinary shapes which steel could assume during a serious fire, 
especially when the metal was loaded, but there was little risk of failure provided the 
girders and columns were completely encased with a proper thickness of some fire- 
resisting casing of, say, cement, brickwork, concrete, fireclav, or other suitable material. 
Local authorities could generally require some suitable fire-resisting covering in public 
buildings, but this practice should be extended to large private buildings. 

If the steel was projjerly encased, say in concrete or cement, it would serve the 
double purpose of protection from fire and oxidation, as cement is well known to be one 
of the best preservatives of steel. In this case the steel must on no account be painted 
or oiled, as the cement would not adhere. The rolling mill bloom should be carefullv 
scraped off the girders, but a very slight amount of rust was not objectionable, in fact 
it was an advantage, as the cement seemed to combine chemicallv with the oxide of 
iron. 

Reinforced Concrete. — It was reinforced concrete, however, that would occupy 
attention in the future. 



E 



sriiHL I'RAMi-: in'i/j)i\(;s. 

Thv cuiniKiraliyely slow dcvHopmont of reinforced concrete in this country was 
chiefly clue to the disasters which had befallen some of the buildinf^s in this material 
in America, but the inquiries afterwards instituted into the causes of the collapse had 
generally proved that a tota disre^fard of the ordinary pro'Caulions durinj,^ (he buiklinij 
had been observed. If shavings and pieces of uood were cartL'sslv left at the foot of 
a column and concreted up disaster must be expect.d ; also if (he links or ho.ipinir w re 
omitted from the vertical reinforcement in columns. 

Another contributory c.-.use of dela.v in .he acceptance of reinforced concrete as a 
n ethod of cons.rucnon had been due to the fact that one effect of our changeable 
climate on a larf-e su,x-rhcial ar.'a of a reinforced concrete building was the cracks 
u Inch were visible here and there in the thin walls. 

Perhaps the first advantage attaching itself to reinforced concrete construction xxris 
economy. I here were practically no maintenance charges, and when thev considered 
I he enormous cost to which railway companies and others were put everv vear for 
painting bridges, etc., this was a matter of supreme imix.rtance, and should not be 
overlooked when comparing the cost of the two stvles of construction 

In the case of buildings, reinforced concrete" sui^^rseded the old-time method of 
budding the walls up from the found.ations, and saved a great .amount of lime and 
consequently of money It was no uncommon thing to witness the curtain w.dls being 
built at three or four different floors at the same time. 

As for strength, it was generally recognise-d that reinforced concrete w.-.s well 
adapted to carry enormous lo.-.ds. and with regard to stabilitv he saw dilliculties ahead 
when the time came to demolish reinforced concrele buildings for particular purposes 
I he .iuthorities would probablv not allow an explosive to be used i i ■ 

Reinforced concrete was also ada,,ttxi to withstand other d.ingerous influences It 
would be diflicult to hnd a better test than that of exposing it to the sulphurous fumes 
from locomotives, and the Austrian .Society of Architects and Engineers had investi- 
ga ed the subject of concrete as applied to the construction of arches beneath which 
railway trains have been passing for periods up to thirteen vears, and in one case 
engines had remainetl underneath for prolonged intervals. ' Careful examinaticin 
demonstrated the facts that the surf.ace of the concrete h.-.d sulTered no iniurv, that 
there were no evide,u-..s of porosity, and that embedded iron was quite free from 
corrosion. ^ 

Matrix and Aggregstes. Only one cement w.is permissible in reinforced concrete 
-tl.-it is, tlie yer> b. st winch could be obtained, and this must alwavs be of such a 
quality as would pass the British Standard Specification. 

.Aggregates of one sort or another were procurable everywhere, but experience 
proved that for streiigth there was nothing to equal hard stones or granite, broken so 
as to pass a j-in. diameter ring .and graded with smaller material" down to about a 
^^'^■^ I P'''^P''''"""^ ye "^"'-'".^- 4 : ^ : ■ -'•..•.. four parts of graded broken stone. 
n%o parts clean coarse sand and one part cement. If broken brick was used, the old 
bricks should be cleaned of the mortar and plaster before placing in the crusher 
travel made a first-rate concrete if proj^erly proportioned, and it had often been de- 
monstrated that round, sm.«th ball.ast gav<. nearly as strong a concrete as broken 

h..,^^'^'"*'^ '''','"■.'""",-' ^I'^-'K'"-- '"■"-•'"'«' mixing gave a more even concrete than 
hand mixing, and the best variety of machine was that known as a " batch " mixer- 

vhlU"' °"i!i K ? '-' hopper or other suitable vessel w.as attached to the machine into 
^^hIch could be placed the correct proportions of aggregate and matrix. Bv turnin- a 

ever the whole of the contents of the hop,>er are discharged into the machine together 
1 '' "'^^''-":"'^ quantity of ^^•.•>ter, and in a few minutes these ingredien"ts are 
buHdin " '^'^-ether, ther.-by resulting in a consistent concrete throughout the 

■ ^°u '''Reinforced concrete building of small dimensions, when the aggregates were 
mixed by hand, if the sand and cement were first of all mixed together with 'the proper 
quantity of water and_ the previouslv wetted broken stone added thereto, and the 
whole thoroughly combined, quite a first-class concrete would be obtained 

Experience showed that concrete used in these frame buildings should be much 
wetter than when required for '"bulk" concrete, as it was found to be better for 
tamping and distributing round the steel reinforcement. 

199 



SOUTH WALES IXSTITUTE OF ENGINEERS. [CQNCBETEl 

Reinforcement. — There were a tremendous number of systems to choose from, 
some of which were patented and others not, but there was no disputini^ the fact that 
no particular s\'stem comprised all the essentials of an ideal reinforcement. Generally 
speaking, each system had features in which one or two details were superior to those 
of other systems, and perhaps this was a good reason why they should study the 
matter themselves or confer with a consulting engineer, who would specify which 
svstem or combination of systems \\<iidd be the most suitable for the particular 
puri>ose. 

Calculations. — It was advisable in llic fust place to study the formula; recom- 
m<.-nde(i by the K.I.B.A., and when these had become familiar there was no difficulty in 
applving the simpler formulae which had been evolved by- various experts. Many of 
the simplified formulae contained constants and perhaps other somewhat empirical 
matter which, in the hands of a man of experience, were useful, but, if used by a 
beginner, might lead to a considerable risk of error. 

Supervision. — In ordinary building construction one generally felt fairly comfort- 
able when all plans had been approved and the contract duly signed, but in reinforced 
concrete work their little troubles only began with the commencement of operations. 
.-\ keen eye must be kept on all departments, including centering, fixing rods, stirrups 
and links, mixing of concrete, taking samples, watching the setting, removing 
sheeting, etc. Of course, the calculations allow a reasonable factor of safety, but, not- 
withstanding that, the supervision must be continuous and strict. 

The dull grey appearance of concrete was undoubtedly very monotonous, and the 
difficulty seemed to lie m adapting it so as to make it acceptable in such tuildings 
where no great architectural tre;.tment was required. When the leaders of the 
profession become familiar with the scientific principles, together with the practical 
construction of reinforced concrete, agreeable elevations in keeping with the conditions 
would be produced. 

THE SOUTH WALES INSTITUTE OF ENGINEERS. 

FERRO-CONCRETE. 

By MR. ROBERT G. CLARK, Assoc.M.Inst.C.E. 

Mr. Robert G. Clark. .issoc.V .Inst.C.E.. read a paper on •■ Ferro-Concrete" be/ore the Soiitli Wales 
Institute o/ Engineers at a recent meeting at Cardiff. .Mr. II'. D. Wight presided, and a number of 
lantern slides were shown of some of the more notable reinforced concrete structures in this country. 

To manv engineers and architects who came in contact with reinforced concrete for 
the first time the following doubts arose, and until some explanation or proof was 
forthcoming, the subject, as far as they were concerned, did not make much progress. 

(a) Did the steel rust or deteriorate when covered by the concrete? 

(h) Was reinforced concrete fireproof, and what proof was there of its 
durability? 

(r) How did reinforced concrete stand shcx;k. vibration and settlement? 

((/) How did first cost and m.iintcn.uice compare with ordinary building 
material construction ? 

Rusting of Steel in Concrete. — With reference to the protective properties of 
concrete ,ind steel, cliemists affirmed that the reason why the steel was kept from 
rusting was that the oxide of iron chemically combined with the cement, forming' a 
covering of ferrite of calcium which was a good protective agent. The author had 
investigated the following two cases in his practice. 

On the River Thames a reinforced concrete pile had to be withdrawn as the result 
of a very severe collision. The pile had been driven about three years to a very hard 
set, as it carried a heavy load. .After being pulled up the pile was laid on the bank 
for inspection. .\t various places along the length of the pile the concrete was cut 
away and the steel exposed. In each case the steel had not the slightest signs of rust. 
On a pier further down the sarne riv-er a reinforced concrete tie-beam, that had been 
in position about eighteen months, had to be cut away to make provision for a 
diagonal brace. The tie-beam was midway between high and low water mark, so that 
it had a severe test, being alternately wet and dry. On examination the steelwork was 
found as good as when put in, and moreover the rust had disappeared. It might easily 



FERRO COSCRKTI-:. 



be imagined in w hat fondition the sleel WDidd have been if it had not bien prolecied by 
the concrete. Ajjain, at Soiithani[)ton in iStjS, several pile heads were cut off and 
thrown on the foreshore, so that they were alternately exposed to the air and covered 
b\- the tide. They were examined some seven years after bv several well-known 
engineers, and they found that the exposed steelwork had greatlv rusted and deteriorated, 
whereas by chipping away the concrete they found that the bars which were embt-dded 
in the cojicrete were as lr<-e from rust as the day that they were jnit in. 

Fire- resisting Qualities.— ['he lirei>roof qualities of reinforced concrete were 
being recognised more and more, as may be witnessed from the number of very lar"e 
buildings that were now being constructed entirely with this material. It had Ix'en 
clearly demonstrated that if the steel were rovered wiih if. in. of concrete it would Ix- 
absolutely fireproof. 

.Many tests had been carried out in which the teniperalure of the structure had 
been raised to 1500° Kahr., and then lloodetl with water, and the only thing to be 
noticed tifter were some fine hair cracks, no doubt caused bv the r;ipid cooling. It was 
also proved that a reinforced concrete wall onlv 4 in. thick' was ample protection from 
lire, as the tem])erature on the fire side of the wall was 1500° l-"ahr., and on the other 
side tlie temperature was only a few degrees above the 0])en air. In the case of fires 
in buildings constructed of reinforced concrete the fire was usually confined to one 
room, as was the case at the warehouse of the Co-o|)er.itive Wholesale .Six-ietv at 
Newcastle-on-Tyne. 

It was worse than useless to have a reinforced concrete floor supported either on 
cast iron or rolled steel joists, unless the cast iron or steel column was also rendered 
firepriKif by a coating of concrete, or, what is better, reinforced concrete should be 
substitulixl. 

Durability of Concrete Ihe durability of reinforced concrete should not be 

ditlncult to prove, as it had already been shown that as long as the concrete covered 
the steel there was no need to have any fear. It was a well-known fact that concrete 
ini])roved by age, and it was also known that the tensile strength and compressive 
strength of the cement also went on increasing year by year. 

So far all tests prove that each year the strength 'of the concrete increases but 
naturally the increase is very little, say, after ten years. The author h;id had the 
privilege of inspecting some concrete made with some of the earliest Portland cement, 
and the concrete resembled the hardest stone, and showe<l no sign of disintegration. 

The cement made to-day was a much belter article, and it was only reasonable to 
expect even bettor results in Ihe concrete. It might be jjointed out that th<Te were 
instances in which the concrete crumbled, .and the author ox]>ressed the opinion that 
this might be traced to unsuitable maleri;ils or inferior cements. 

Resistance to SAocArs.— Probably the most remark,-ible characteristic of reinforced 
concrete was its ability to withstand excessive xibration and shocks without injury 
.\ most convincing proof of this st.ilement was the large number, running into tens 
of thousands, of reinforced concrete piles that had lx-<-n successfully driven into ballast 
and other hard strata. In most cases the monkey weighed from' two to three toils 
and the blows came in sharp succession so as to keep the pile always on the move.' 
Take the case of locomotives running over a bridge and subjecting it to shock, small 
m quantity, but frequent in action, due to the engine travelling. 'The bridge dellects 
under load and springs back as soon as the load is released without developing any 
cr.icks. The .Messina earthquake ahso gave striking examples of the resistaiice of 
reinforced concrete to shocks. Regarding settlement it would be readily understood 
that reinforced concrete had a strong point here, as the whole structure was monolithic 
.nnd could take tension as well as compression. .Any tendency to cant sets up tension 
in some member which in ordinary construction n'lade itsel'f evident by cracks and 
fissures. It couM be easily demonstrated that the tension bursts might' be prevented 
by using steel rods. 

Cos*.— Regarding the cost, sneaking generally, reinforced concrete was from 10 
per cent, to 40 i>er cent, cheaper than ordinary construction, and this without taking 
into account the advantages already investigated. The first cost was the only costi 
and maintenance charges, that were a constant worry and expense to engineers in 
charge of railways, bridges, docks, gasworks, etc., were entirely obviated. 



SOUTH WALES INSTITUTE OF ENGINEERS. [COSCBETE] 

The properties of concrete were, that it was weak in tension, stroni;- in C(ini]jression, 
comparatively cheap, and a reliable protective covering for steel. On tlic other hand, 
steel was strong in tension, rather expensive, and unless protected from the weather it 
ra]>idlj- deteriorated. 

Reinforced concrete might be divided into three sections, viz. : Design, .Materials, 
and Workmanship. -As the materials were of a special qualit\ and cliaracter it might 
be permissible to give them attention first. 

Steel. — The steel should have a tensile strength of about 27 to 31 tons, and an 
elastic limit ranging from 15 to 16 tons. It should be made to stand the usual tests 
of the British Stand.ard Specification as regards bending. All steel should, wherever 
possible, be bent cold, and if it must be heated great care should be taken that it was 
not warmed above cherry red. Welds should be avoided, as lapping the bars about 
thirtv times their diameter was more satisfactory and reliable. Any loose scale should 
be scraped off, but the bars should not be coated with paint, oil, or cement wash. 
Each beam must be designed to complv with the individual conditions, which so very 
rarelv coincide; the s]ian, fixation, load, and jxisilion of the load are four vari.able 
factors. 

Cement. — This should be of the best Portland cement, complying with the British 
Standard .Speciticalion. It should be free from gypsum, especially for setting under 
water. With the modern methods of manufacture the cement of to-day was truly a 
scientific article, and as such demanded scientific treatment if its strength was to be 
brought out, as opposed to the rough-and-ready handling that it often met W'ith at the 
hands of the average labourer or foreman. The author had no hesitation in stating 
that it was possible to get results from 50 per cent, to 100 per cent, better than ten years 
ago if the cement were treated properly and intelligently. The question of setting 
time for reinforced concrete work was often the cause of trouble, and very often the 
concrete had commenced to set before it had been placed in position ; the subsequent 
ramming and tamping only served to opixise the setting of the concrete. The quantity 
of water used was often left to the discretion of the labourer, and varied considerably. 
Concrete often took a week or so before " going off," but in most cases, where it had 
been obtained from reliable makers, it would be found to harden all right within the 
s]iecified time. 

Sand. — Tlie sand should be clean and sharp, and of various sizes from § in. 
downwards. It should be free from shells, clay, earthy or vegetable matter. 
\'erv fine sand should not be used except as a small proportion. Fine sand gave a 
larger area for the cement to cover, with the result that the mixture was greatly 
weakened. 

Aggregate. — It shuukl be .l h.ird stone, and where granite w;is easily obtainable it 
should be imi\ersally used. It might be urged that granite was expensive, but this 
difficulty fell to the ground when it was remembered that it would safely stand about 
twice the crushing stress that most stones crush at, and, as the same quantity would not 
be required, it might be regarded as economical. The sizes should vary from | in. to 
f in. This should .also be free from qu.-irry refuse .and all foreign matter, and, if 
necessarv, washed. 

Water. — The water should be preferably fresh water free from acids, grease, or any 
vegetable matter. Clean sea-w.-iter w.-is not prohibited. In order to reduce the voids 
to a minimum it would be as well to make a few experiments with the proportions of 
sand and stone, to see which gave the best results. If all sand were used the mixture 
would be poor and weak, and on the other hand, if all large stone were used a rich 
mixture might be obtained, but it would be full of voids, and thus render the steel 
subject to rust. For marine work and ])iles the cement should be increased, say, about 
10 per cent. 

Mixing. — The concrete should be preferably machine mixed, but if mixed by hand, 
as was common on small jobs, it was a wise precaution to increase the cement. As 
soon as it was mixed it should be taken in small quantities to the work and well tamped 
in, so that it was well ])acked round the reinforcement. 

Workmanship. — Even with the best materials and design there yet remained a 
most important factor that might upset all the calculations, namely, workmanship. It 
could not be too strongly emphasised that if it were not properly carried out and super- 
vised very indifTerent results might ensue. Contractors, foremen and workmen 



IM 



FERROCONCRETIi. 



require si^cial tiaiiiiiif,'- anil education in this class of \vori<. In all cases it was advisable 
In have a coMipetent sLipervisor, who should always be stationed on the work. Ik- 
should see that the materials were up to the specification, check the sizes and number of 
bars in a beam, floor or column, .also see th.at they were in the iKisilion shown in the 
drawing's before concrctins;: was allowed to commence. Me should also see that the 
concrete was placed in position without disturbing the steel, and see that the tamping 
was done without forcing the steel out of its proper position. 

.Ml moulds, centering and shuttering sl.ould be of well-seasoned timber. The 
joints must be close, so ,as (o prevent leakage, .and the timbering should be designed 
strong enough, so th.at llie weight of the materials did not cause the limber to undul\' 
dellect. 

Before concreting be allowed to commence gre.it care shoidd be l.iken lo see that 
.ill s.iwdust, chips, etc., arc cleared away. 

The construction of beams, d(>cking and floors had often to be interrupted before 
completion, and in such cases the edges of th.e concrete .should lie roughened with a 
cutting tool and then thoroughly cleant^d from all loose and foreign m.itter. To this 
rough surface neat cement grout should be applied with ;i brush, ;ind the concrete 
sliiiuld then be immediat<'ly pl.-iced in ix>sition and r;inime<i up to the old work. 

In the ca.se of columns there was a great s.iving to be derived by adopting 
reinforced concrete. Pl.ain concrete was liable lo fail suddenly, and it cJccupied an 
excessive amount of space. .A step has been t.aken in the right direction bv embediling 
rolled steel joists for columns in concrete; but this is not economical comp.ared with 
reinforced concrete. Provision should be m.iile for eccentric loading, so that the steel 
should be plactd to the best ;idv.iiU;ige, th.it is, as f;ir from centre of column as 
possible. 

^enera//y. — Reinforced concrete h;id been .ipplied lo many, it iiol .ill, i\|:i> of 
engineering ;ind architiclural work. What the growth of reinforced conerele uould 
be during the next five or len ye.ars w;is a matter of speculation, but the .author ventured 
to think that it would be very much in adv.ance of the past \'\\'o v<Mrs. .\t the present 
time the subject w;is occupying the attention of the leading engineering and .architec- 
tural institutions, and there were signs that they were giving reinforced concrete their 
■■ictive support, even if some of the many proposed regulations were rather academical. 
So far the local building laws of the cities and boroughs h;id somewhat hampered the 
development within their jurisdiction, but as a general rule after 'the pl.ans h:ul been 
explained .and inspected they h.ad been passed. .'Mready London, Glasgow, Liverpool 
and Manchester had amended their by-laws in orde'r to complv willi reinforced 
concrete conditions, so tli.n in .1 leu ve.lrs doululess otiier cities .and boroimhs would 
follow their lead. 



IliOS ASD STEEL JXSTITUTE. 

IRON AND STEEL PRESERVATION. 

P.iier by MR, ALLEKTON S. CUSllMAX. 
.•1; Ike aimuul meeliiig ni Ike Iron and Slid Inslilulc. held recenllv at Weslminsler, at which Sir 
Hugh Bell, Bart., presided, an important paper was read by Mr. Allerton S. Cushman, Assistant- Director 
ot the United States Office of Public Roads. 

Mr. Cushman pointed out thf necessity for a preservation of manufactured iron and steel, in order 
to secure the conservation of supplies. .\ further interesting point was the security of modern concrete 
buildings reinforced with steel. If, he said, steel reinforcements rusted away, it boded ill for the future 
of many modern structures owing to the impossibility of making inspections and repairs before the 
danger point was reached. The records of discussions before a number of engineering and scientific 
bodies showed that there was conflicting evidence and opinion in regard to this subject. There could 
be no doubt that the reaction of unleashed cement concrete was strongly alkaline owing to the separa- 
tion of free lime at the time of set. If this alkaline reaction was maintained, steel embedded in the 
concrete should remain uncorroded. If, however, as was sometimes the case, percolating waters 
found their way through the concrete, the free Ume would e\ entually be removed and dangerous 
rusting take place. Nails and other objects of steel would remain bright when immersed in lime 
water, and the author had found that the addition of about 5 per cent, of quicklime to soggy, sour 
clays and soils w.iiild have a very decidedly protective effect on steel embedded in them. It was 
curious that this simple expedient had not been resorted to in order to prolong the life of steel pipes, 
lines trenched in soggy clay soils, where there w.as but little movement of soil and subsoil water. 



NEW WORKS IN CONCRETE. 



(CONCRETEl 



NEW WORKS IN CONCRETE 

AT HOME AND ABROAD. 

r;„ ,,, this heading reliable Information -will be presented of neiv -u-orks ["^'""■^' "f 
Unaer tlus heaaing reaa J selected -will be from all parts of the -world. 

'^t:::zip!:^^o-d:p£tf^^^^ 

and ilhistrale their primer), features, at the mist txpiatnmg 
for the design.— ED. 



KEINFORCED ARMOURED CONCRETE DOCK WAREHOUSES AT MARSEILLES. 

A-r the beginning of the v. u - ''^ ^'-;;^-,,::; j'^:;^^:: ^./p;;^^^ 

placed in competition two dock ^varehou^e.. 1 he ^chenu 1 

the fan thai the other s'""l"'>7'*»~'jr'„'"™jf™dan,ts in reinforced 

e::2r^:^,S:^"'-v-£S^':;^^r;e^^^^ c.e.. e.a.ina- 

irof the advantages offered by fhis matena. over stee UvoH.. ^^^^^.^^^^ ,^^. 

About fifteen schentes m steehvork and in ^^^ "'"^^^f JXtdct Ensjineer. Thev 
the Chief Engineer of Br.dges and V^ays and ^i^ ^ Je D,s nc^^ ^^g ^^^^^ ._^ ^^^^ 
decided, with the approval of the t^^hamber °' "- ° ^^'^ ^^^^ '^„ economy over steel 
S:nSt^i^:^ofX^totrS <3:::^rS^aL o.ered the other "advantages 

- ^^s-' -=s i-nufs^^f :^^^ ? p--' '" -- -- -- 

building measuring .05 ft. in width and 77>t|n lengthy ^^^ ^_^^ 

Eiich warehouse is composed of a g.ound floor, pavcti 




General view of warehouses. 

/-^v-^-LT-c n.irw WAREHOUSES AT MARSEILLES. 

Reinforced Concrete uuck v> akhhou. 



204 



ty. C^CiNSTPIKTIONAI.l 



AV-:/A7--OA'C/.7) CONCRHTI-: \V A RHIIOUSBS 



a first floor covered uilli asnliali lli,- ,-,„,i ;, ii.,. ,,,, i i ■ , 

material and >.ravel. ' ' '^•" ■"'^' "'^'■'■'■'' ^^"'> ^vaU-r-prooCni: 



Facing the quay Ihe first n,„>r i. constructed to .supoorl •, cr 
uiner side the Hat roofs ol the warehouses project over ,o fi. u 



railway line. 

In /'"/.i;. I we show .1 -in, 



!• road. On llie 
irrn sheher lo ;i 



il till' warehouse 




RlilNFORCEn CONCRE 

The first floor has l,een constructed for the unl.,.>dini,^ of jrrain. Wcial elev-.lor^ 
convey the tjr.-nn from the steamers on to ihe first floor on w h , h jl^'"''". ';":^•"orS' 
The grain may then_ be unloaded into vva,.,ns hv m";.s of ts in tht'lw^^^^ 
u-h.ch are fitted special lubes. When .he ^'oods -arrive in ba/^s the -.re , ' ' 

hy electric cranes and conveyed ,0 the ..round floor U^ Z^K^^^^V '.".^ 
doors have been provid.-d on Ih,' inside face of the buiMin.vs 1 ,. 1 V ' , ^^ 
be loaded into the .rains running alon.ysi.le Iih^' .ar h, ' '! 1 ^ ''^ '^ '"■■'■" 




the Si n/ ^^The foundations, the pier is composed of wooden piles dr 

ootino^rnf , J • '^""'T f"^'"''''"'"'^ has been made on the top of the piVs 
foundation ''" " ^"'"'^"^ '"""''"^ l'"'-'^ ■^^^ '-"'t ^"^ectly upon 'this ordinarv 

exceSon'of'H'"''' °f "^^ '^"ildi'lJ^'^ '- ^'nlirely made of reinforced concre. 
exception of the small-end eleva.ions. which are made in brickwork. 



iven into 
and the 
concrete 

with the 
205 



SEW WORKS IN CONCRETE. 



The longitudinal elevations are made of bricU panels supported b, reinU-rceU 
concrete lintels and pillars aructure are shown. 

]S/^ :£:^l^ort"S^^^e%.c^^<>u. .3 ft. centre to cen.re transversely 

""''ihi^fl^o^it^lfi'Sosed of principal bean.s and secondary hean.s supporting 
a slab 6 in. thick, covered ^'^ll^V are spaced at the same distance centre to centre on 

The pillars on the fi^^^^A^^l'^J^^^Pd floor, but there is only one row of pillars. 
» '""fi— i ::rbrs^p^C,|X roof a. therefore ^.^ >"--,, ,, 
_-Vt;r^Ss^^;^^^r p^lj^et^;^^^^^^^ covered with . in. of 
''""'tn the beams of the floors and roof are, according to the Coignet system, known 
as " .Arm.iture of equal resistance. 




Owing to the considerable length of ;he b.iHdingJt ^^^^^J^^'^'^ 
divide the floor into six portions of about 13 > ft. each, 
from the others. K,.t„-^pn the reinforced concrete lintels and pillars 

Stanchions. , . ,^^„,.- .^j („, bv means of four staircases. Each 

huildS ^^:<^w-S:r.r l^f ™S^^S doors. Half of these are on tl. 
'''''t:Z^:t^t:o:r^^c^^^^^'^^ tl. contro, of the Dock Engineer, 
and prt^^l'olt satisfactory. J^t, ^ti^^d^^TgL TnKd^^^e^^complete erection 
of j:^rSint"S"tt ^el^cfplr'tfShe foundations, and machinery and 

^^"^T^; works were begun on the 1st Jan.ar> t.oS, ^ ^J^^^;,-^^ ^l t 
f^rst building was finished at the end « ^ ^^ ^ > • .^^^^^ ^ , half monthi after. . 
second building on the .5th September-namely ^^g"^ ^ renderings, brick- 

^j'zr'':^^:^i^^'^^^^^^'^^-- -- ->-- -^-^ ^^^ ^-^^-"'"^^ 

°^'^h:°Sk was executed in ten ^o^:^-^l^:,l-;:i;j-^.^£:'' 
probably a maximum of fifteen months to-s-ct these w r^^ ^^^ foundations, was 

The total annount of *- jnt^^ -th the e. _^p^^^^^ ^^^^^^ ^^^^^ ^^^ ^^ 
;;g;r S: iMo^: ^^r^s a^ood example of the economy of using concrete. 

206 



/. ICNf lUIHTiaNAl.I 



REIS FORCED COSCRETB CULVERT. 




REINFORCED CONCRETE CULVERT Al 
KILTON. 

U',- illuslralf in llii> article a reinforced 
concrete culvert, which has been built under 
the North-Lastern Raihvay line between 
SlvMininf^'rove and Killon, to provide i 
waterway at the bottom of a valley, which 
IS at present spanned bv a viaduct. 

The work was designed throughout bv 
the fc.nj,'ineenni,' Deixirtnient of the Trussed 
Concrete Steel Companv, Limited, of 
Caxton House, Westminster, S.W., under 
the suiKTvision of Mr. VV. J. ('udworth, 
late e hief Lnfcmeer of the North-Eastern 
Kailway and the requirement was that the 
cu vert. should be surticientlv stronjf to resist 
subsideiice due to mining,' operations below 
.n addition to the weight of a high embank- 
ment. 

The piers of the viaduct, which rise 
about ISO ft. above the bottom of the 
valley, having shown siprns of subsidence 
the railway company decided to construct an 
emb.-mUment across the valley underneath 
the viaduct, which was consequentiv to U- 
discarded. The embankment is to be" carried 
up to the present level of the rails, and will 
probably be, when finishixl, the highest in 
England. 

The culvert, as will be seen from the 
drawings, is of unusual size, the thickness 
ol the reinforced concrete at the crown 
being iS in. It is of large area, having to 
accommodate great volumes of flood water 
at various times of the year. Owing to the 
bad nature of the ground forming the sides 
ol the valley and the extra pressure brought 
upon the culvert by carrying up an embank- 
ment of the height required, the inlet and 
the outlet had to be designed of unusual 
strength to prevent the sides being forced 
in by the earth pressure outside, .and it \\as 
found necessary to put in reinforced concrete 
struts under the floor, both at the inlet .uid 
the outlet, so as to prevent the rel.-.ining 
walls from sliding towards the centre of the 
culvert. The total length of Ihe culvert is 
AS" 't., and the reinforcement of the arched 
portion IS entirely composed of Kahn trussed 
bars. 

The embankment is now being filled up 
with shale taken out of the mining pits on 
each side of the valley. 

In designing the' culvert the full pres- 
sure ot the earth filling the embankment 
150 ft. high was taken into consideration 
and the conditions required bv the railwav 
company were that the calculations should 
be based on the assumption that onlv one 
side of the arch was loaded, this bein"- 



NEW WORKS IN CONCRETE. 

ViLW of end of Culvert. 



ICQNCBETEJ 




208 



M 



Ri-:i\r()RCh:i) concrete culvert. 




Delail section and elevation of Culvert. 
RsiNFoRcED Concrete Cui-vert at Kilton. 



209 



NEW WORKS IN CONCRETE. 



((jQNCRKm 



happen in case 



the -round settled under one side of the culvert. 





f&^JS^m^arS/^ RKINFORCHD CONCRETE SILOS. 

I'lHin complilion, ihc iiilvcil was tested with rails to (lie full workiiij;^ load of 
5 tons per sii[>er foot, in the presence of the North-Easlern Railway Company's 
eng^inoers, the rails being loaded on the crown of the arch only. The culvert was, 
therefore, not assisted by any side pressure which would have been exerted had the 
testing- material been built right round the arch. .V dellecting instrument was placed 
under the crown of the .irch before the test began, .and druly observations were made 
during ;i whole week. There was no deflection, .ilthough the test load w.is allowed 
to remain in position for several days. 

REINFORCED CONCRETE SILOS AND WAREHOUSES AT 
SELBY. YORKS. 

Tlie silos and wareliousi-s, .il-.ii convcxor bridge-. illu>lr.ilc(l on the op|)<jsite page, 
were constructed in reinforced concrete by Stuart's Granolithic Co., Ltd., of 4 Kenchurch 
.Street, E.G., for the Olympia Oil and Coke Co., Ltd., at Selby, Yorks. 

The overall dimensions of the silo are 11 1 ft. 7 in. by 93 ft. 7 in. and 35 ft. high. 

There are 54 bins in all, each u ft. 15 in. centres, with a total capacity of 5,7ix> 
tons, all of which may be unequally distributed — i.e., one bin may be full while the 
surrounding bins are empty. 

On top of the bins are a series of gangways, the lo.id for the floors of these 
gangways being 2 cwt. jxr ft. sujx'r. 

The floors of the w.irehouses alongside the silos are all in reinforced concrete and 
are 5 in. thick, inclusive of granolithic linish, this thickness being required for the 
enormous traffic which circulates over them. 

The weight to be carried by the floors of the warehouses is 4 cwt. per ft. super, 
safely distributed over ,unl above the static weight of the structure. 



NEW USES FOR CONCRETE. 



ICQNCRETEJ 



NEW USES FOR CONCRETE 

AT HOME AND ABROAD. 

Under this heading reliable information ii'ill te presented as to netv uses to vjhich concrete 
and reinforced concrete are putr 'with data as to experience obtained during the experimental 
stage of such ne'w applications of these materials* The use of reinforced concrete as a 
substitute for timber in exposed positions is one of the Questions of the moment, Pailtvay 
sleepers, telegraph posts, fence posts, etc., of concrete are being tried. Similarly, efforts 
are at present being made to pro've that reinforced concrete is an excellent substitute for 
bricktifork, iiihere structures of great height are rejuired. —ED. 



CONCRETE BLOCKS FOR BUILDING PURPOSES. 

The illustrations of the houses in this article are excellent examines of the use it 
concrete blocks for buildings. This method of construction is very useful where 
economy of time and labour is essential. 

The design of the Bungalow at the Garden City Suburb, Bilton, is very attrac- 
tive, and the boundary wall of the bowling green at Bilton, illustrated below, is also 
formed of concrete blocks, and presents a very pleasing appearance. 

These concrete blocks have many advantages. They are easily laid, which saves 
a lot of expense in the erection of a building, and the inside face of walls built with 
blocks is so even that only one thin coat of plaster is required, which is also economical. 
The blocks are lasting, fire-resisting, and cheap. 

The blocks used in these buildings were made by Chas. A. Nettleton, contractor, 
of Harrogate, and the Newcastle Grindstone & Pulpstone Co., Ltd., of Newcastle- 
on-Tvne, on the " Winget " Concrete block making machine, the proprietors of 
which are the C K. \\'inget Concrete Machine Co., Ltd., of Newcastle-on-Tyne. Their 
machine moulds hollow or solid building blocks at the rate of 300 32-in. by g-in. by 9-in. 
per day. 




Concrete Blocks. 



COXCRIiTE BLOCK llOL'SliS. 



C'OTTAl.B AT W.M.KEK GaTK. N 1 WCASTLEUSTI NK. 




iiltf 



1^ 




HUNGALOW AT BiLTON. HaRKOGATE. 

Buil: of "Winae:" Co.icrete Blocks. 



NEW USES FOR CONCRETE. 



ICONCRbllU 



FLOATING REINFORCED CONCRETE DOCK. 

^f o fl<->Ti;n<T reinforced concrete dock erected at 
T„. il["^'-^'l-%-^.;'^;7M":srs G. A? Whitehead & Co., contractors, who use it 
S^rSr unCd't^do,^!^ fol^^s^nd and gravel, and find it far su,.nor to any wooden 

-'%rS.:it£rr^hr^r::itS:t^^^iSe:^^n:!:t;'^ the nver was fun of 

recently been frozen ni rne ^^^ ^^^ ^^^j. .^^ harbours. 

"' ^Thfrock :rs receni te^^^^ thoroughly, and with most sat.sfactory results. 




ED Concrete 



A METHOD OF CONSTRUCTING REINFORCED CONCRETE FLOORS. ETC.. 
A MEIHOU Kj WITHOUT SHUTTERING. 

THE method of constructing reinforced ^^""//'^ ,!';";V^;„;rInd "o^^^ 
boarding, and the labour in erecting and retiTOV.ng the shutterin,. 
214 



^ 



REINI'ORCHD COSCUHTE I-LOORS. 



Lifiht steel T-joisls i)r other sections are placed at suitable distances apart, and 
t<Mnpi>rarily supported by a prop in the middle. Concrete slabs, previously prepared at 
the site or elsewhere, are then laid to form the lower surface. Concrete beams or a 
concrete lloor are consiructed in place, as shown, the boardinj^ required 
for Die lie.ims in the second lijj;-ure being; removed as soon as the concrete has set, in 

^a , b ,ci. 






^ ' - -^ 



d b 



^•.t:>>2 



i,\i/!± 



Al.TKHNATIVK MKr>lt>DS OF CONSTRUCTION 




I— 1^ days, and apiin used. The upper parts of the steel joists serve as part of the 
reinforcement, ami other roinforcin^ rods are introduced where necessary. Insulatinj; 
material, sand, etc., may be filled in above the slabs, and a wooden flo<ir laid above. 

The lower fij»-ure on this paf^e represents a floor carried on all sides by the \val\^. 
Square wooden frames, a, are the only centerins^ required. .-V ceiling divided into 
compartments may be constructed as shown in detail section, the slabs b being 
previously prepared and laid on the flanges of the joists, a. Beams c are constructed, 
and a filling d is then added. 

.\rched roofs may be consiructed similarly by bending the T-joists to the required 
curve. For columns, the concrete slabs form the outer surf.-ice, the corners being com- 
posed of angle-iron. 

The system is recommended by its simplicity, and by its low capital cost, especially 
where wood is scarce. 

Particulars as to this method of construction may be had from Mr. J. Virck, 
architect, of Malchow, Mecklenburg. 



NEW USES FOR COS CRETE. 



ICQNCBETEJ 



T-BEAMS AND T-BEAM FLOORS. 

Mr. N'irck has also sent us particulars of a patent which he has taken out for another 
method of constructinsj floors. In tliis system floors and ceilintrs are carried by 
T-beams, thus economisinij concrete. The flooring may then hv ol less thickness on 



i± 




account of the reduced distance between the beams. If the T-beanis are still further 
broadened, as in the lower figure in our illustration, tlie intervals may be tilled by thin 
concrete slabs or by brick arches. The T-heams are then made of correspondingly 
diminished height. 

The hollows thus left in the floor may then remain Ojjen at the top during con- 
struction, and serve conveniently for the reception of pipes, for holding insulating 
material (b), or as ventilating passages for the lower rooms. In this way a cheap 
sound- and heat-proof floor is obtained. The lower concrete slabs should be about 3 cm. 
(15 in.) thick, and the upjier 3 — 4 cm. (ij — li in.). 

The T-beams are built into the supporting walls at the ends, and if of long span 
they are supported by a column in the middle. In order to guard against lateral thrust 
or shock during building', the edges of the plate are reinforced with rods (c). 

REINFORCED CONCRETE CHIMNEYS IN MEXICO. 

While not a new departure in liie held of reinforced concrete, two chimney stacks, 
designed by H. Eckardt, engineer, and recently constructed by Carl Leonhardt, 
contractor, of Los Angeles, California, in connection with pumping stations for the 
Cananea, Rio Yaqui and Pacific railroad in Sonora, Mexico, present some features of 
interest and at the same time evidence increased faith and favour for this class of 
work. 

The two stacks are located at Kilo 4, South of Guaymas, and at Einpaltne, the 
former having a height of 105 ft. and inside diameter of 4 ft., and the latter being 
150 ft. in height and with an inside diameter of 6 ft. 6 in. 

The foundation for the stack at Kilo 4 is circular in form, having a diameter of 
20 ft. ; is cast on piles and reinforced with i-in. steel rods in web system with 9-in. 
centres. 

Upon this circular base is mounted, in the shape of a fru--tum of a cone, another 
mass of concrete with a 20-ft. base, an .S-ft. lo-in. top, and 3 ft. in height. The 
completement of the foundation is reached with a concrete cylinder, having an outside 
diameter of S ft. 10 in. None of this is visible in the finished stacks, the three sections 
forming a monolithic mass. 

The superstructure of the stack proper presents the appearance of two super- 
impcised cylinders, the lower having an outside diameter of 7 ft. 10 in., the upper 
6 ft. 10 in. There are three stages of decrease in the thickness of the inner and outer 
walls, four in the vertical reinforcement, and two in the horizontal. The general 
section presents an outside wall or shell, an air chamber in five equal compartments 

216 



m 



iiicr 



REINFORCED CONCRI-yrii CHIMXEY. 

ilU. .-.nd 



c;,s,nu „> ui.lil, in ,-.-,li„ l„ lb,. |„.io|„ ,..„M ,|,.crc..-.sc. „f outt-r a,ul inn. 
II inner or (lue \v;ill. 

The lower section or cvlind.r is ;„ fi. in h,.i,.hi hn. ^n out.i.l,- uall of ,2 ,n., 



fl. in hcij^lit, h.i 




imt' 



■- jriKHi 




presenting, to L o t nkivlew th '^'^^""'j^''' '''"^ ^ 5-n. nue wall. The last section, 

-11 of 4hn;;in;;^;!,x?:nd"a^t;nX":-:^/'^ '''°"' ^'="'°"- "^^^ -'^'^-^ 



^EW USES FOR CONCRETE. 




The reinforceme>n consi^ e.nirel>^of t.MsteJ_^^ 
proportion to the height. .he lovxer j( 
with thirtv-six equally spaced 
i.in. rods, the flue or inner 
wall with eighteen ^in. rods. 
Horizontallv, the same sec- 
tion has l-in. rings, spaced 
24 in. centre to centre; in the 
outside wall T%-in^ nogs, 
spaced i8 in. in the flue wal 
The remaining 75 ft- °^ ^^'^'^ 
have a uniform horizontal re- 
inforcement of i-in. rings, 
spaced 24 in- in the outside 
wall, and i-in. wall rings, 
spaced i8in. in the fltie wall. 
The vertical reinforce- 
ment for the next 31 ft. con- 
sists of eighteen i-in. rods in 
the outside wall and nine 
I.in. rods in the flue wall 
Following this are 28 ft. with 
eighteen |-in. rods in the out- 
side wall and nine i;;in. rods 
^^ Ute flue wall. The last 
section of .6 ft. has eighteen 
a.in. rods in the outside wall 
and nine J-in. rods in the 
flue wall. 

The forms used weic 
built in Los Angeles and 
shipped to Empalme; the> 
were constructed m 12-n 
lengths for the outside and 
6-ft lengths for the inside ; 
this stack had the scaffolding 
that carried the working- 
platform, also the screws for 
lifting the forms. The air- 
chambers were lifted by hand, 

required for the work "j^ "^^^^pf ^^„, to suit the design. 

for the same being built ot . n • - ^^„„,^ .^ SYRACUSE. U.S.A. 

REINFORCED CONCRETE S^;^";^'^ f^^( reinforced concrete construction 
The Stadium recently buiU at Syracuse Ln.\trsit> .. ^ ^ 

•'^^'^rSneral dimensions of ^^^^^ ^^ :^Jf'^^-^f^^r.rS^V^^; 

there is a promen.ade of ^;;""'^''^- 
by a concrete curb 2 ft. wicie. 

218 




CRETE C 



RHIN FORCED COSCRKTE STADIUM. 



The whole superstructure is supported on concrete piers, the footinj,'s for which 
iire carried down to solid soil. Where no fill existed the footin),'s extend 4 ft. 6 in. 
Iielow ih.' t;r(.uiKl. The m.iin girders .-.re j ft. deep .ind 1 ft. wide. 




The approach to the main entrance consists of concrete stairs and platforms, and 
two stairways of reinforced concrete also lead from the ground floor to the offices 
wtiich are located in the towers, which are about 16 ft. above the field. 

On the outer edge of the promenade surrounding the structure are placed orna- 
metal concrete posts 2 ft. sq. and q ft. high. On about everv third post an arc lamp 
is located with electric conduits encased in the concrete post. ' 

219 



MEMORANDA. 



ICDNCR ETEj 




Memoranda and Ne-ws Items arc presented under this heading, ■w.th occ.swnal cJ.tor.al 
comment. Authentic news -win be -welcome.-ED. 



CONCRETE INSTITUTE ANNUAL GENERAL BUSINESS MEETING. 

The Concrete Institute have sent us the foUoNving account of then" hrst annual 

meeting, together with a copy of the Council's report :— 

The first Annual General Meeting of the Concrete 1-;''^'?,;^^? '^^'J, j^,' 'l^ 

Roval United Service Institution, Whitehall, on Februar "th. the R'g It H^n-^^e 

Earl of Pl>,nouth C.B.Oa.e ^^'^t ComnnssK>ner of Vorks,, ^^^ ^e as rer Mr w! 

supported bv Sir Henry lanner, I.S.O., Mr h.. f. \\ eus, J.r., nun. 

Dunn, F.R'.I.B.A., and other members of the t-O""'^''' j^ ^- g yice- 

letters of regret having been read from Sir W lUi.im '^^■^ee':e, KA, .ii., n ite 
1 etters oi le^ p ^ others, the result of the ballot tor 

Ad^m;; M.Inst.C.E.; Messrs. William G. Kirkaldy. .Usoc.M.lnst.C.E. , J. S. E. de 

Sir Henrv Tanner seconded, a vote ot thanks to me r-.ni . 

on this occasion and for his services to the Institute. 

REPORT OF THE COUNCIL. 

^ InJial Conim^^^ be^n formed from time to time to attend to yanous 

-"T;;;^^G^:r!5nS.::^,S,^:Sich'£;tr^held for the presentation and 
discussion of papers, haveT^een most successful, the attendances bemg sat,sfactor> 
and the discussions of considerable interest. _ 

Transactions of the Institute, contaunng pape s r, ^ ,i,u e hnve been 
discussions and other information concernmg the work o, the In^tUute, ha\e 
published from time to time. 



.CDNyrBucTioNAiJ MEMORA NBA . 



r 1. CDNyrBUCTKaMAlJ 



Diiiinji llic summer momhs arraiifJleinLiils were made by which members of 
the Ijislilule had an opportunily of visiliiifj works and other places of interest. 
These visits, wliich were attended by a large number of the members, were of an 
instructive cliaracler. 

The tlianUs of the Institute .ire due to the authors of the papers and to those 
who acted as hosts on the occasions of the visits referred to. 

Besides the organisation of these meetings and visits, the Institute lias clone 
much useful work in other directions. There are two ntatters which call for 
special attention — namely, the part it has played in the .Amendment of the London 
Building .Act, and its efTort to introduce .i Standard Notation for Reinforced 
Concrete. 

With reference to the first ni.iltir, the Council of the Institute felt that, 
althougli a young Society, it ought to have a voice in the .\mendment of the 
London Building .Act, so far as that .Act affected reinforce<l concrete structures. 
Accordingly, the House of Commons was petitioned by the Institute and various 
conferences were attended by its delegates. It is satisfactory to report that the 
new .Act recognises the representative character of this Institute, and that it is 
now one of the various bodies which have to be consulted in the matter of 
regulations for reinforced concrete construction in the County of London. 

.Again, a most useful work may l>e said to have been initi;ite<l by the suggested 
Standard System of .Algebraical .Symbols to be used in calculations for reinforced 
concrete. The matter has aroused considerable interest both in this country and 
abroad, and it is hoped that the list of symbols prepared by the Science Standing 
Committee will be soon adopted by the English-speaking nations. 

With regard to the fin.inces of the Institute, it is satisfactory to note that in 
spite of heavy expenses necessarily incurred by the Incor|X)ration of the Institute 
and by Parliamentary and other matters, these expenses h.ive all been met, 
and there is a small balance in hand. 

The Council gl.idly welcome suggestions which are made from time to time 
with a view to increasing the influence and usefulness of the Institute. Some of 
the suggestions are here set out in order that members may have an opportunity of 
considering and discussing them. 

1. That a series of meetings should take place once a year on two or three 

consecutive days. Papers could then be read and discussed, and the .Annual 
(iener.d Meeting could be held at the same time. It is thought that this 
arrangement would make it worth while for members living at a distance 
to come to London for the purpose of attending. 

2. That branches of the Institute be formed in provincial towns for the benefit 

of those memlx^rs who reside in them. 

3. That a Graduate Section be formed of Juniors who are anxious to study 

technical matters in concrete and reinforced concrete. 
In accord.ince with the Rules of the Institute six vacancies have occurred on 
the Council, and these have been filled by ballot. 

The Council has to report with sincere regret that Mr. .A. E. Collins has 
resigned the position of Honorary Secretary. Mr. Collins finds that he is unable 
to attend the meetings of the Institute owing to his time being fully occupied by 
an important public .'ippointment. He will continue, however, to remain a member 
of the Council, and to give the Institute his co-oiX'ration and assistance. 
Reinforced Concrete Dam at Afeo/coit.-^H.M. Consul at St. Louis has for- 
warded an extract from .-i local p.iper, from which it appears that it is intended at an 
early date to begin work on the construction of a reinforced concrete dam 5,800 ft. long, 
37 ft. high, and 37 ft. wide at the bottom, across the Mississippi River at Keokuk, 
with a view to the generation of electric power for supplying the City of St. Louis. 
The cost of the work is estimated at 12,000,000 dollars (about 772,500,000). Further 
details, given in the extract referred to above, may be seen by British firms interested 
on application at the Commercial Intelligence Branch of the Board of Trade, 73 
Basinghall Street, London. E.C. 

Tenders for a Reinforced Concrete Bridge. — The Corporation of Merthyr 
Tydfil invite tenders for the construction of a reinforced concrete public road bridge, 
76 ft. span, over the River Taff at Merthvr Vale, and for other work in connection 
therewith. .A copy of the specification, together with a general drawing giving plan. 



MEMORANDA. ICDNQJEJEJ 

elevation, section, and cross-.ections of the suj^gested bridge may be obtained from 
T Flete ler Harv^v, Borough Engineer, Toxvn Hall, Merthyr lydhl, upon payment of 
i-2 Is (which will be returned on receipt of a bond-fide tender, accompanied bv 
detailed drawings of the work, and description and weight of steel remforcement). 
Sealed tenders, endorsed " Aberfan Bridge," must reach Mr. I Aneuryn Rees, lown 
Clerl- Town Hall Merthvr Tvdtil, not later than noon on Saturday, March I2th, iqio. 
The Corporation do not bind themselves to accept the lowest or any tender. 

Reinforced Concrete Culvert at Macclesfleld.-The Highway Committee of the 
Corporation recommend approval of tlie scheme of the I^.rough burvevor to diver ta 
culvert in a straight line from Commercial Road to the River Bolhn in a 2i-.n. 
reinforced concrete tube, at an estimated cost of £M I2S. 6d. 

Reinforced Concrete Oas Condult.-.\ pressure main of reinforced concrete, 
.6 in diameter inside and 334 ft- long, is in use at Salt Lake City. Ihe maximum 
static head which it withstands is about 20 ft. of water. The thickness at the top of he 
section is 6 in., and at the sides 7 in. The bottom is constructed in the form of a 
section of an octagon, with a minimum thickness of h in., and the reinforcement 
consists of i-in. square twisted steel bars, spaced S in. on the centres. This conduit 
has been in u.e .even years, and, according to the City Engineer, is in hrst-class 
condition. . , „, 

Proposed Cliff Improvement at Clacton.^-M a recent meeting of the <-lacton 
Vrban Council the Sea Defence Committee reported that the recent heavy gales had 
caused damao-e to the wooden sea wall and Promenade, and they had directed that a 
concrete buttress be constructed at the point where the piles had been thrust forward, 
and that a concrete apron be constructed for a distance of 20 ft. on each side. 

Bridge over the T/6er.— The municipality of Rome, after considering com- 
petitive tenders from several firms which make a speciality of construction in rein- 
forced concrete, has just entrusted to the Societ.^ Porcheddu Ing. Giov. Antomo, of 
Turin, the work of building a new bridge over the liber in the neighbourhood of the 
Pia/za d'.-\rmi fuori Porta del Popolo. -,, a ^ • 

The bridge will consist of a single arch with a span of 100 metres, with a flat rise 
of I in 10, and the roadwav will be 20 metres broad. The cost is estimated at ^-So.ooo. 
The work is to be finished in the exceptionally short period of 15 months so that the 
bridge may be readv in the early part of 191 1, at the inauguration of the International 
Exhibition which is to be held at Rome in that year. • • r ■ 

The structure, on which work has already started, will be carried out in reinforced 
concrete and it is proposed to face the bridge with artificial stone resembling limestone. 
The roadway will be paved with cement and asphalte, on the special system of the 
.Societa Porcheddu. , , ,, , 1. .u 

Concrete Po/es.-Concrete poles hexagonal in shape and hollow through the 
centre are used bv the Oklahoma Gas and Electric Company. A 35-ft. .pole measures 
7 in. across at the top and t6 in. across at the butt. They are moulded in forms made 
up of c-ft sections, so that it is possible to cast a pole of practically any length. Stee 
rods are placed symmetricallv about the ceiitral axis and at the top and bottom project 
throu-h holes in steel plates.' The rods are bent over at each end and securely- fastened. 
The core which is wrapped with one thickness of building paper, is suspended within 
the form bv wires at intervals along its length. The concrete used consists of a mixture 
of one part cement, two parts sand, and three parts chats or zinc tailings. 

Cement Tanks in France.-The American Consul at Bordeaux in a recent 
report drew attention to the French utilisation of the improved cement tanks lined 
with «lass Several vears ago cement tanks began to take the place of wooden tanks 
in a number of the larger wine storage houses. One of the reasons for this substitution 
appears to have been the cheaper cost of material for cement tanks, as the price for 
timber had been gradually rising, and even at the higher prices was scarce and difficult 

*° ""Threffort to place acid-proof linings or coating on the walls of cement tanks seems 
to have proved of slight value in the matter of ameliorating the conditions^ of absorp- 
tion The idea of coating the walls with squares of glass, tightly joined with cement 
is said to have solved the difficulty, as a tartar forms on the thin surface of cement and 

"^'""^Thes'eTank^s^'are'particularlv useful as storage receptacles for wines, alcohols 
ndies, liqueurs, ciders, oils, gasoline, kerosene, turpentine, etc. It is said that 



brandies, liqueurs 
222 



|&E.NtiiNLi',kiN(. ~J MhMOi-iAi\ DA. 

tanks so coiislruclcd are neither affected bv hiiniiditv nor by infiltrations, that thev 
resist fire and inundation, and liave a further .idvant.-ifie in 'tliat thev are not li.ibl'e 
to lie struciv In- Iightnuij* as are tanlcs of metallic material. Variations of temperature 
ellect a minimum loss by evaporation, the def<ree being reported at less than i per 
cent. .\1 equi\;ilent tem|)erature wooden tanks lose between 6 and 7 per cent. 

Reinforced Concrete Conduit in Mexico CIty.—h w.is recentlv reported that 
comr.icis uere .about to be made lor the con>truclion of four large reinforced concrete 
con<lu.l> m Mexico Cty, to exleml to all parts of the cilv in which water is supplied 
In the Mumcip.il (.overnment. The conduits will be between 2 and 3 metres in 
.liameter, and will, together, have a length of m.mv miles. It is understood that 
the work will not be completed for three vears. In addition to this work, new and 
heavy w.iler pipes are to be installed in all p.irls of the cilv. 

Reinforced Concrete Poles for Electrical Wor*. -There are, as is well known 
a number ol types of reinforced concrete poles now in use, but, according to / <• Ciiiiie 
( n;l. I he Societi Bresciana Cementi e Costruzione de Brescia have recentlv designed a 
new t\pi- which is being used on the tramway between Mestre and Trevisa It is 
lozenge-shaiK'd in section, the curves of the lozenge being concave. The core consists 
of eight iron rods at the base ,ind four at the top of the pole. These poles carry a 
10 mm. trolley wire .and three 4 mm. wires, the span being 40 metres. This gives rise 
to the following stresses, the wires being supposed subjected to a wind pressure of 
70 kg. |)er square metre operatinj,-- on a cylindrical surf.ace (1-4 metres above the section 
considered : Moment due to the weight of trolley wire 6i-6 kg. ; moment due to the 
wind pressure on the wires 394 kg.; moment due to wind pressure on the poles 344-4 
kg. ; .iddmg 25 (X-r cent. (200 kg.) for curves, etc., makins,' a total pressure of i,ooo"k.g. 
at the b.-ise (.<■., i(,r3 ki,'. applie<l at a point (y 1 metres above ground. 

Concrete Pavements.— Concrete pavements have been laid upon .1 numbrr of 
streets aiul brid-es in .Memphis, Tenn., according to Ihe Miimdpal jounuil and 
kngnuY-r. n one place 500 ft. of street were p,-,ved with 1:2:4 concrete, (> in. thick, 
consisting of I ortland cement, sand and equal i)arts of crushed limestone and crushi-d 
granite; after seven years' use the ij.-.venient is said to be in e.xcellent condition except 
for a wulth of 4 in. along the rails of a street, car line. .Another section was l.iid in 
1903 upon a reinforced concrete bridge and the surf.ice was finished with granolithic 
top, 1 1 in. thick; up to the present time it is said that no repairs have been necessary 
I bree other bridges and a number of streets have also been i)aved with coiK-ret<' within 
the 1,1st two years and have shown no appreciable wear. .\n e.xperiniental strip 
4,300 ft. long, was put down between the rails of a street car track and for 2 ft. beyond 
the outside r.ails. It consisted of a concrete foundation on which was placed a '',-in 
concrete we.-inn.i,-- surface. This construction, it is slated, has not been entirely satis- 
factory, .111(1 all concri'te is now ni.uU- monolithic. 

Some experiences with Cement. lined Pipe. iVom .1 recent paper bv Leonard 
.Mete:, II eonsulimg eiii^meer, Boston, the fullowin- inierestin- experiments with 
cenicnt-lineil pipe are taken : 

'■ Brockton, Mass., has a 20-in. and 24-in. pipe, .about -, miles long, one-h.ill ,>f it 
running through a country district, the remainder throui,rh one of the'outlyin<-- stre<-ts 
of the city. 1 he latter half of the main has numerous connections. The ori<Hnal pipe 
shell w^as dipi>ed in hot .-isphaltum ;ind rolled in cement and sand before bein-- placeJd 
The lower end of the m.-iin is under .about 50 lbs. pressure. The Superintendent states 
that there has been no ir.niblr to >,K'.ik o.f with this m.iin during the twentv-eiirht years 
of Its existence. 

■' <^"o"<:o''d, Mass., h.as two lo-in. pipes, ,ipi>roxim;itely 2* miles each in length, 
the hrst in the year i,S74 and the second in the year lS.S,. Both pipes are still in active 
service and have given comparatively little trouble from leakage. The maximum 
static pressure is approximately 40 lbs." 

Proportioning Crusfied Stone for Concrete.— Accordma; to .Mr. .\lfre<l .Mover, 
Assoc. .\m.Soc.C.E., a .saving in cement and s.ind mav be elTected and a much denser 
concrete obtained it two or three sizes of crushed stone are used, proijerlv proportioned 
and mixed together. A simple method is as follows : ■ - r i- 

^ Supposing you have two sizes of stone, one passing;- a li-in. ring, the other passin" 
a 4-in. mesh. Screen the |-in. stone, taking out all that will' pass throuijh a i-in mesh'' 
figuring that which screened out as sand. Make a receptacle which will hold approxil 
m.itely 4 cu. ft. (a piece of ij-in. sewer pipe will do). .Measure 2 cu. ft. of the smaller 

223 




t^ V^YY^T^r^OT^T'F »^<^ONSTRUCTIONAlr 







A practical handbook to the economi- 
cal employment of Portland Cement 
for the house, garden, stable, farm, etc. 




Published by 

THE ASSOCIATED PORTLAND CEMENT 
MANUFACTURERS (1900) LTD. 

Portland House, Llojds Avenue, London, E.G. 



Price 2 6 net, post free. 

Presentation Copies will be forwarded to Members of the Engineering 
and Architectural Professions upon application. 



ri.coNSTuuiTioNAti ^IH^u)RA^'I)A. 

ift. ENGINJ^INO — -J 

stoiic ami 2 cu. 11. of the larger stone, mix them well together with a shovel and jjlace 
in the rt-ceplaele, mark the receptacle on the side the heiglit to which the stone rises. 
Kniply llie receptacle and a^'ain measure out 2^ cu. ft. of the larger stone and li cu. ft. 
of tlie sni.-iller stone. .Mix together as before, place in the receptacle and note on the 
side the height to wliich the stone rises. Experiment in this manner varying the 
prn|x)rtion of the larger and smaller stones, always adhering to the total quantity of 
4 cu. ft. The mixture which gives the least volume in the receiJtacle will make the 
densest concrete, and require the least amoimt of sand and cement. " Maximum 
density is m.iximum slrenglh." 

Attractive Surface Finish for Concrete. \n American jjaixr gives the following 
method of providing ,in attractive surface finish for concrete : 

Erect forms of rough boards by the usu.d methods, in courses of 3 ft. or less. 
Plaster inside of forms with wet cl.-iy, work to a plastic consistency which will .adhere 
to the forms. Corners m.iy be rounded by this method, and by indent.-itions bead work 
.and otlier designs can be .accomplished. 

While the clay is wet, apply evenly loose bulT, red or other coloured sand, after 
which, ]X)ur in the concrete bv the same method as applied to ordinary wet concrete 
construction ; remove forms in usual time and after cl.ay is dry, wash olT the clay with 
water, and if necessary scrub with a brush. The sand will thus adhere to the concrete, 
giving a surf.ace of |)leasing colour .mkI texture. 

TRADE ANNOUNCEMENTS. CATALOGUES. ETC. 

The Chain Concrete Syndicate, of Leeds and Casilefurd, h.ive issued a neat 
bimklet, sluiwing photngrapbs .ind dr.iwings of sonic ini|K>rt.-int works in reinforced 
concrete ricenth uiulerl.ikcii by tliem, .and incorporating some articles relating thereto 
which have appeared in the teehnic.il Press. .V distinctive feature of this firm's 
svstem consists of their .-idapl.ition of a patent clip, to proviile against the possibility of 
tiie steelwork getting out of [)lace during the process of concreting. These clips are 
made from Hat bar steel \ in. thick, and from i in. to ij in. broad, according to the 
position which they occupy, and are cut by special machinery to the exact patterns 
required. 

The Expanded Metal Co.. Ltd., York Mansion, London, .S.W., have issued a care- 
fidly arranged pam|)ldet dealing with " Expanded Metal Lathings for Plaster Work," 
which will, we have no doubt, be foxnid both usefid and interesting^. They remind us 
(h.it their expanded n>etal has been in successful use all the world over for the |>ast 20 
years. It is made from sheets of rolled metal of various thicknesses, cut and expanded 
l)v machinery into meshes of different shapes, each of which is made in several 
strengths or weights. The ^-in., 5-in. and i^-in. mesh lathings, which arc made from 
sheets of rolled steel, are well adapted to form a key for pl.ister in ceilings, steelwork 
encasing, partitions, exterior walls, etc. The s|>ecia'l concrete meshes made from 
sheets of rolled steel are specially suit.able as reinforcement for concrete in foundations, 
walls, floors, roofs, arches, bridges, reservoirs, dams, sewers, conduits, etc. The 
three types of expanded metal lathing — i.e., the diamond mesh, cup mesh, and the 
square mesh, are illustrated and described, and general instructions as to 
spacing, meth<xls of fixing, etc., are also given. Other matters dealt with are 
suspended ceilings on exjiimded met.al lathing (profusely illustrated), steelwork en- 
casing, thin walls and partitions, stairs and stepping, and light framed buildings. 

Particularlv interesting are the descriptions of cottages built at the Garden City, 
Letchworth, ot which illustrations and sectional drawings are given. These cottages 
are built on a raft of concrete, with hollow w.ills of wood studs, ex[Xanded metal 
Lathing and cement plaster. The illustrations show the framework in course of 
construction as well as the completed building. 

Richard Johnson, Clapham & Morris, Ltd.. of Lever Street, Manchester, have 
sen: us a comprehensive and useful catalogue, excellently produced and illustrated, 
descriptive of their reinforced brickwork and the clothing of steel-framed and rein- 
forced concrete buildings. In this system the reinforcement consists of a wire mesh, 
2 in. and 25 in. wide, with respectivelv three and four straight tensional wires running 
its entire length. When embedded in the mortar joints of the brickwork, this mesh 
forms a continuous bond, and the mortar, instead of being a filling only, becomes the 
strength of the brick wall. Plans of cottages of reinforced brickwork to cost ^130 
each, and descriptions of fireproof partition walls are also given, in addition to a 
number of interesting tests, with photographs, which have been made to demonstrate 
to architects in various parts of the world the additional strength given to walls when 



MEMORANDA. 



[CDNCBETEI 



reinforced with H. B. patent wire mesh. The catalotjue also includes examples of the 
different thicknesses of walling', with useful tables for calculating the cost of con- 
struction, and the weight and volume of various substances. 

Edwin J. Pearce & Co., Ltd., Leicester, have published a well printed and 
artistic list, showing coloured illustrations and drawings of their various specialities, 
as well as jjhotographs of work executed by them in reinforced concrete. Among the 
advantages which the firm claim for their reinforced concrete fireproof and soundproof 
floor, are lightness, strength, rapidity and ease of erection, also that the cost of 
centering is saved, this not being required. The flooring slabs are made in lengths of 
4 ft. and are about i ft. 6 in. wide. They are recessed at the ends to fit on to the 
bottom flange of the light steel girders, space being left for a grout of cement to 
protect the flanges of the girders. Messrs. Pearce & Co. are able entirely to finish off 
all work which they undertake, as they make a special point of their wood block and 
parquetry floors, Roman and ^'e^etian mosaic work, etc. 

The (U.K.) Winget Concrete Machine Co., Ltd., of Northumberland Street, 
Newcastle-on-Tyne, ha\e just received from one of H.M. Government Departments a 
further order for another " Winget " concrete machine, complete with ordinary outfit, 
pallets, etc. There could be no more convincing proof of the merit of these machines 
than the fact that (Jovernment Departments are giving repeat orders for them. 

James H. Tozer 6t Son, Ltd., of York Mansion, York Street, West- 
minster, have asked us to state that Mr. Percy Tomey is no longer in their employ as 
agent, engineer or manager of the Reinforced Concrete Department. 

W. <S G. Foyle, 135 Charing Cross Road, W.C, have sent us a copy of their new 
catalogue of technical and scientific books, and call attention to the fact that nearlv all 
the volumes included therein may also be obtained from them second-hand, at about 
half the published prices. .\ny book will be forwarded on approval. 

Edward Lomer <S Co., Ltd., of no Fenchurch Street, E.C., have been 
appointed by (jauhe, Gockel S: Co., of Oberlahnstein, Germany, as sole representatives 
in the L'nited Kingdom for the sale of their builders' and contractors' machinery and 
appliances, concrete mixers, etc. 



A NEW PROCESS 

FOR FIXING IN REINFORCED CONCRETE 
FLOORS, ROOFS AND WALLS WITH- 
OUT THE USE OF SHUTTERING 

This process considerably cheapens the cost of 
the concrete construction, and is indispensable in 
districts where there is a scarcity of timber. 



NEW HOLLOW 
CONCRETEFLOORS 



Those interested, in England and the Colonies, may 




NEW T-BEAM 
FLOORS 



obtain further particulars of the invention from 

JOH. VIRCK, Architect, Malchow, Mecklenburg, Germany. 



CONCRETE 

AND 

CONSTRUCTIONAL ET^GIT^EERING 



Xolumc \'. No. 4. l.oNlxiN, Al'Kil., 1910. 

EDITORIAL NOTES. 



REGULATIONS FOR REINFORCED CONCRETE. 

I\ ihf present issue we are presentintf an interesting contribution on the 
r|uistion of rctjulations lor reinforced concrete in the metropolis fr:.m the 
|)<n of Ml'. William Dunn, I'. I\ , I . H. A. , whose \ie\\ s \vc invited on the 
subject. 

It may be remembered that .Mr. Dunn was one of the leaders cf that 
enthusiastic band of opponents to the London Building .Act .Vmendments last 
.Session, wlun the question of the regulations for steel frame structures was 
belore the House of Commons. Mr. Dunn's views were gwnerallv adverse t:> 
the regulations, and the detailed regulations in particular, and neither the 
Kuilding .Act nor its administration seems to find much favour in his eves. 

It is alwa\s of considerable value to be able to present views seriouslv 
given on a subject of this kind, no mi;lter how much we may disagree with 
them, for, in the first place, arguments such as Mr. Dunn's mav influence 
those in authority against over-regulation, and on the other hand thev show 
those same authorities the dangers of the absence of proper regulations. 

The arguments put forward would, of course, be very much in place il 
the Code .Napoleon were in force m this country, and the responsibility, both 
personal and pecuniarly, were definitely defined so far as building owners and 
architects wero coiuerneci, and the first result of any accident were, as is the 
case in some countries, immediate imprisonment of those controlling the build- 
ing operations, who are, ipso facto, assumed to have been negligent until thev 
can proNC their innocence. The Code Napoleon, however, is not in force in 
(Ireat Hritain, and — as long as the pecuniary and personal responsibilities are 
not clearly dilined by a legal code — detailed regulations are absolutely essential 
in our \ iew il the public are to be safeguarded against carelessness or 
ignorance on the part of those who undertake the erection or supervision of the 
construction of buildings. 

A\'e belong to those who consider the .Amendments to the London Building 
.\ct oi last year to be excellent precautionary measures and very practical 



CEMENT TESTING. [CONCRETE] 

ones, except in the matter of a few details. We shall welcome a detailed code 
of regulations under that same 15aildinij Act Amendment dealint^ with reinforced 
concrete. 

We considei the publii are amply guarded against anv o\ er-regnlation 
on the part of the London County Council by the fact that the Local (lovern- 
ment Board must approve the proposed regulations and have to consult various 
technical societies regarding their utility. 

We certainly hold that the regulations, when framed, should cover all 
reinforced concrete used in a building, whether internal or external; and in ad- 
vocating the careful regulation of reinforced concrete in the metropolis we 
think that this will iie a great safeguard for the reinforced concrete industry, 
which is still \'erv much in its infancy. 

The first serious accident to a reinforced concrete structure in the metro- 
polis, iinoKing loss of life, w c uld mean a set-ljack for this industiy, not onlv 
in London, but througiiout the entire counti-\' ; and everx thing which can be 
done within ri-ason to pn\ent such an accident should be done by the authori- 
ties on public grounds, and should also be looked upon as beneficial to tlie 
professions and industries concerned. 

-Vs to some of the more general remarks of Mr. Dunn in his able article 
regarding the building regulations, and their administration in the County 
of London, our view is, taking the capitals of Europe generally, that it is 
easier for the building owner and his pi'ofessional advisers to get to work in the 
metropolis than anywhere else; and, speaking generally, that the administra- 
tion of the regulations by the district surveyor on the one hand, and by the 
London County Council and its principal officers on the other, is equitable, 
efficient and courteous, hi fact, it is far less irritating to the building owner 
and the architect than in any other capital. 

Regardless, however, of our views on this subject, we recommend Mr. 
Dunn's article to the attention of our leaders as a most useful contribution on 
the svibject, and ue in\ite their correspondence in reply to the arguments he so 
abh' puts forward. 

CEMENT TESTING. 

A \'EKV interesting paper relating to (he testing of Portland Cement was 
read b\- Mr. D. B. Hutlir, F.C.S., at a meeting of the Concrete Institute on 
March 17th, in which was raised again the ver\- important question of the 
relative value of the methods in \oguc for determining by accelerated tests the 
soundness of cements for constructional work. 

From the title of the paper we note that the test selected for criticism 
was that of Le Lhatelier, which test enables a quantitive determination of the 
qualitative eccentricities in regard to the expansive properties of Portland 
Cement to be made. 

The test is still one of the principal features of the British Standard 
Specifications for Cement, and we understand that, notwithstanding its severity, 
it has been accepted b\ all manufacturers of repute, the product of whose works 
has been much impio\'ed b\ their successful endeavours to comply in detail 
with the requirements of this test. 



usc( 



[A-L^^i-^£^T;ri^l IlOLl.OWAY MONBV ORDER OFFICE. 

In our issue <>i July, (k;illni; uilh Mi. II. K. (; Harnlxr's p;,],,,- ,,n " Tlu- 
Setting of Porliand Cement," \vc piihiislied :i rcpDrt on a similar subject, in 
which the opinions of Monsieur Lc Chatelicr himself were expressed on points 
of criticism of bis method which were then raised, and in the course of his 
recent lecture Mr. Butler makes reference to points raised in this earlier paper 
and reports the results of some very carefully conducted experiments, which 
in the main confirm the corirlusions arrived at by others who have earlier 
dealt with this subject. 

There appears to be a xaricty of opinions a^ to whether this test, losjether 
with others which Mr. Rutler enumerates, errs on the side of severity as com- 
p.in-d with the nuihod adopted by the late Mr. Henry Faija. 

The author of the paper, who has a wide experience in these matters, 
• leals with his subject in a most able manner, and inclines to the retention 
f the less sever/- tests of the past, and one cannot help realising- that cement 
sed in the past which would not comply with such .severe tests as the 
l.e Chatelicr have not all proved faulty in construction. 

I'^or ourselves, we incline to the more searching tests of the Le Chatelicr 
uirthods, especially as they do not seem to impose any particular hardships 
on the manufacturers, and the user should undoubtedly prefer to use a material 
which had passed the greater rather than the lesser test. 

THE HOLLOWAY MONEY ORDER OFFICE. 

It IS with great pleasure that we are again giving some particulars of 
I'..st Ofl^ce work executed in reinforced concrete under the direction of His 
M.ijesty's OfTice of Works. In this instance the building is for the Money 
Order Department at Iloll<,w.,v. These continued examples' of structures in 
Ihc new niat.'rla! executed for our public departments are far greater evidence 
and testimony to the utility and ( conomy of reinforced concrete for general 
pinposes than any amount of argimient or special pleading on our part. 
THE NATIONAL ASSOCIATION OF CEMENT USERS. 
The National .Ass.Kiation of Cement Users of .America, of which Mr. 
Richard L. Humphrev, M..Am.Soc.C.E.. is the President, held their sixth 
annual Convention at Chicago from February -rst to the 25th. The Association 
nre certainly to be congratulated on the success of the Convention, the meeting 
being the largest ever held by the .Association, over 350 members attending. 
The papers presented were more than usually interesting, and we regret 
that they came to hand too late for insertion in this issue. We shall, however, 
deal with them at some length at a future date. 

Reinforced concrete was given its usual prominence in the proceedings 
of the .Association, and a great deal of the time of the Convention was devoted 
to the discussion of proposed standard specifications, the most important being 
regulations for the use of reinforced concrete, which were accepted by the 
Convention, but which now have to be submitted to the .Association as a vvhole. 
The President was particularly anxious that members should endeavour 
to spread the knowledge of the .Association's standards, and we shall publish 
the reports and discussions on these at a later date for the benefit of our 

B 

229 



PORT OF LONDON DUES. [CONCRETE] 

readers, as the standardisation of methods is a matter of great importance, 
especially in the case of a new industry such as reinforced concrete ; and we 
think that there should certainly be co-operation, wherever possible, between 
English and American engineers and architects on this matter. 

PORT OF LONDON DUES. 
Effect on the Cement Trade. 

The Port of London, the largest shipping centre in the world, was for many 
years hampered in its development by lack of adequate funds. The administra- 
tion was in the hands of various bodies, and the docks were, to a large extent, 
out of date. From time to time various proposals have been made to get over 
the difficulty. The various dock companies were unable to raise more capital, 
having failed in the times of prosperity to provide adequate reserve funds for 
the renewal of obsolete plant and the proper maintenance of their undertakings. 
\'arious enquiries were held from time to time, and at last, in igo8, an .-Xct 
of Parliament was passed vesting the entire control of the port in the hands of 
a body to be elected by the various interests concerned, and providing for the 
purchase of the docks. 

Hitherto London, though a dear port for shipping, has enjoyed the great 
advantage of entire freedom from dues on goods. In order to provide the 
revenue for the necessary expenditure to thoroughly equip the port by bringing 
the existing, docks up to date, constructing a new dock, and improving the 
Channel, Parliament has authorised the levying of import and export dues. 

The Port .'\uthority recently issued a schedule of the proposed dues which 
brought forth loud protests from all circles. The Board of Trade appointed 
Lord St. .'\ldwyn to hold a public enquiry, and the various objectors have been 
urging their case before him. The interests are so diverse and conflicting that 
it was soon apparent that no settlement could be arriv'ed at which would be 
satisfactory to all parties. 

The case for the cement trade and allied industries was taken up b}' the 
Cement Section of the Chamber of Commerce, who appointed its chairman, 
Mr. Charles Charleton, of Messrs. I. C. Johnson & Co., and Mr. Alfred 
Brooks, one of the managing directors of the .Associated Portland Cement 
Manufacturers (1900), Limited, to appear on their behalf. 

The total value of the imports and exports of this trade amounts to about 
;£?2,2oo,ooo per annum, and the contention put forward was that the contribu- 
tion from this traffic, which only uses the docks to a comparatively small 
extent, should approximate the average levy from the whole trade of the port, 
which would involve an average charge of about _^i,5oo. The schedule 
provided for a maximum rate totalling ;^ri9,ooo, but it became apparent as 
the enquiry proceeded that the actual rates which would probably be levied 
would amount to about ;£r8,ooo. Considerable reductions were secured on 
various items, but upon coal a reduction of only id. per ton was secured, and 
the rate on cement itself was not altered, so that the trade will have to bear 
an annual burden of about ;^6,ooo, unless more favourable consideration can 
be obtained when the matter again comes before Parliament when the pro- 
visional order is presented. 

230 



^ 



■pONSTBDCfiOTJAfl 
EMOTNtFJlNCi — J 



lisp; 



h'l-XSi'f.ATIO.WS FOR RHI .\ FORCED COSCRHTE 



^vH^ i -^. REGULATIONS for REINFORCED ^^i 
"ri^-^y^^ /ij-, CONCRETE BUILDINGS 

^^Ji^'iL^i^—^ IN LONDON 



if^^' 




By WILLIAM DUNN, F.H.IBA, 

In presenting this Article by Mr. Wtlllam Dunn ive ivoula refer our rejtders to our Editorial on 
the sublect, from which It luill be seen that, tvhllst vie are not in agreement -with the Author's 
views, 'we consider that the article deserves careful attention, as an argument by one of those 
members of the technical piofesslons 'whose views are against regulations. — ED. 



Under the General Powers Bill, igog, the London County Council may prepare 
regulations governing the erection of buildings or parts of buildings in Re- 
inforced Concrete, and it is generally understood that the odicers of the Council 
are now engaged in drafting the proposed rules. 

I conceive that those responKible for the new regulations, whether as 
members or ofllcers of the Council, or the Societies which are to be consulted 
before those regulations become law, may profitably consider the objects and 
limits of such enactments — what things should be governed by the law and 
what are best left to the individual. 

The proper limits of the function and duties of Cioveriumnt must always 
be uncertain, to be settled rather by the weight of argument ^n particular cases 
than by abstract principles. But we must call to mind the evil results which 
arise from the acceptance of rash proposals made by sincere lovers of improve- 
ment, frequently intensifying the very evils which they sought to remedy. 
There is the " Merchandise Marks .•Xct," requiring goods to be stamped with 
the name of the country of origin, which is said to have lost us some of the 
trade it was designed to improve ; there is a Bill for the protection of workmen 
in a particular industry, by restricting their hours of labour, which, after some 
experience, does not seem to improve the workman's condition; there are the 
"Model Bylaws," advcn-aled, with the best intentions, as a method of 
securing good and healthy homes for the poor. We know that the Bylaws 
have operated rather adversely, by keeping the country people in old and 
insanitary houses, because few can afford to build in the manner prescribed. 
The results in this case are now so well known that many of the requirements 
as to walls and details of construction have been abandoned. 

Under these Bylaws, however, there is a safeguard of some value to 
the individual, in that the "Summary Judicature Act" gives the magistrate 
before whom appeals are heard power to hold any bylaw in any particular 
case unreasonable, and to decline to convict. 

The County Council are now to make regulations which differ in some 
subtle way from bylaws, and it will be very desirable for all interested to see 
that there is sonie appeal from the Council's decision. 

B 2 2 .1 I 



WILLIAM DUNN. l<jQNQ3ETEj 

The British dread of that extension of the province of Government which 
Continental peoples welcome, both in theory and practice, is gradually breaking 
down, especially in regard to building. A Vice-President of the Royal Institute 
of British Architects, .Mr. J. W. Simpson, in a very able letter to The Times 
on the " London Building Acts Amendment Act of 1905," called attention to 
" the appalling list of Acts regulating building in London," quoting some eleven 
different Acts. A\'c have now a twelfth in the Act of igio, not to speak of 
" those countless bylaws, schedules and regulations on every conceivable 
subject — from the laying out of streets to lamps and clocks, and the exact 
pattern of caulking for an iron pipe — to the rather darkening of the under- 
standing " (I quote from Mr. Simpson). 

That we are to have yet another set of regulations, with all the force of 
law, is due to the necessity of freeing us from restrictions which should never 
have been imposed. 

Just as in the daily conduct of life there is much which falls short of a 
high standard — nay, much which is worthy of reprobation, yet not subject 
to legal restiiction, because the general opinion of our people has hitherto been 
that the evils of over-government are greater than those arising from too much 
liberty — we may fully agree that some method or material is the best, and yet 
strongly object to its use being made compulsory. For such a best may be 
but temporarily so, until another appears ; and occasions may arise in which 
that " best " is undesirable or a sheer waste of money. 

No fixed rules or regulations can take account of all the circumstances or 
cases which may arise, and it is not an uncommon experience to find that the 
District Surveyor has to insist upon something being done which he is quite 
willing to admit is unnecessary or would be better left undone. 

We know how the development of reinforced concrete construction in this 
country has been kept back by our building laws. The earlier London Building 
Acts formed the model for the laws in all our English and Irish towns, and, as 
they did not recognise that concrete could be strengthened by steel, the 
administrators of them had no choice but to require the same thickness of wall 
for reinforced concrete as for plain concrete. Fortunately the earlier Acts were 
confined to matters affecting party walls, external walls, the prevention of 
fire, and other such things, so that we were free to work out and use reinforced 
concrete in internal construction 

In many cases it forms the cheapest, the most stable, most sanitary, and 
most fire-resisting method. To debar the community from using it in any way 
for which it is fitted, as for external walls, is a loss to the country for which 
there is no corresponding advantage. 

In my view we should be careful to avoid any extension of restrictions on 
building not absolutely essential for one or other of the objects for which 
Building Acts are required — for the prevention of the spread of fire, for public 
health, or public safety. 

Building Acts should not contain specifications, but be confined to such 
general requirements as are necessary under one or other of these headings. 
During the discussions on the clauses relating to steel construction, in the 



l&rS'^ii^gS'iN'frti] REGULATIONS FOR REINFORCED CONCRETE. 

London County Council General Powers Bill, 1909, the building codes of 
American cities were frequently cited as examples to justify the inclusion of 
minutely detailed rules. At that very time it happened that Xew York had 
undertaken a revision of its building code, and the Press and professional men 
of New \ork were endeavouring to amend it, citing on their side the absence 
of minute detail in European laws. Thus the Engineering Record of July 24th, 
1909, says : 

The Building Code discussion that has been taking place in New \'ork 
for some months has resulted in some forceful comments on the general type 
of building code so prevalent in this country. For some reason or other 
which it is dilncult to ascertain, our building codes are gradually becoming 
building specifications rather than regulations for the purpose of enablint^ 
owners to secure safe structures at a minimum expense. The difference 
between the elaborate details of the average .Vmerican code and the building 
regulations of leading European cities is a striking one. The foreign 
regulations stipulate merely those features of engineering practice which must 
be followed in the design, leaving the architect and engineer to elaborate the 
details of their plans in accordance with such rules. Here it is becoming 
customary to adopt regulations covering many other things than the principles 
of safe design, and as a consequence the complexity becomes so great that, 
even with the best of intentions, grave injustices may be done to property 
owners by discrimination against certain forms of useful construction or in 
favour of certain classes of material. It is diOicult to comprehend, in fact, 
how a code of such complexity as that proposed for the City of New York 
can be drawn, even by a board of experts, which will not be, subject to strong 
criticism as favouring or disfavouring some form of design or construction 
which experienced specialists consider perfectly suitable. It is only neces- 
sary to recall how opinions have differed in debates before the .American 
Society of Civil Engineers on standard specifications for steel structures, to 
appreciate that a building code, covering in the same way a great number 
of materials other than steel, is bound to be the subject of strong criticism. 
\VhiIe this journal does not believe that .-Vmerican engineers should turn to 
Europe for precedents in all manner of engineering and architectural matters, 
it is strongly of opinion that we have a great deal to learn from the building 
codes of the Continent. By adopting the simplicity of these foreign codes 
the likelihood of favouritism, intentional or unintentional, towards certain 
forms of construction would be largely avoided. 

The Concrete Institute, the Institution of Civil Engineers, the Royal 
Institute of British Architects, and other societies, spent their funds freely, and 
members gave their valuable time, in endeavouring to secure greater freedom 
and to save the ratepayers unnecessary burdens in regard to steel construction, 
and succeeded in so altering the Bill that, whereas the Council sought uncon- 
trolled power (a power which would be exercised not really by the Council, 
but by its officials) to make reguh-tions governing reinforced concrete, its pro- 
posals must now be submitted to the great representative institutions and 
obtain the sanction of the Local Government Board before they become law. 

233 



^VILLIAM DUSN. {CO^CRiLVU 

I would appeal to those responsible for the drafting of the regulations, 
and to the Institutions who are to be consulted, to agree in making these the 

governing ideas : ■ ■ < 

(i.) That the object of the regulations is to give the citizen the power 
to use reinforced concrete for walls. 

(ii.) That the use of it should be hampered by as few restrictions as 

possible. 

(iii.) That the regulations should not take awa) any freedom we now 

have, but remove restrictions only. 

In that well-regulated country, Germany, there are minute rules for re- 
inforced concrete, as for most other things. I do not regard that country as 
affording a model in all things, and I hope that, instead of endeavouring o 
ZZdc ^very possible rule, our aim will be to exclude every rule not absolutely 
elntLl in\h'e public interest. The individual is usually the best judge m 
matters affecting himself; let us not take away from him, with hi. freedom 
that responsibility for his actions which would largely go if every detail ot 
construction had to have a Government stamp of approval. 

I understand that in Germany the architect and builder escape readily from 
responsibility if they can show compliance with the building -g"l-;'-^ J" 
France on the other hand, the building regulations are of the simplest 
Jharac^^r, but the responsibility of the architect and builder remams for a 
definS p;riod of years.' In England we have the burdens of both countries^ 

The use of reinforced concrete for floors, pillars, stairs, roofs etc. has 
steadily developed, without any such series of accidents as would call for 
pectl restriction, and without proving that the trade of the reinforced concrete 
constructor is a dangerous one, to be specially regulated by Act of Parliament. 
The London County Council, under section 23, sub-section i, maj make 
regulations with respect to the construction of buildings wholly or partly of 
rrforced concrete, and with respect to the use and composition of reinfor ed 
concrete - It is to be hoped that the clause .7, inserted at the 'nstance of the 
pro esstnal societies, w^hich enacts that " nothing in this part of this Act or in 
anv regulations in force thereunder shall take away or prejudice any power, 
"ihts privileges or exemptions vested in or enjoyed by any person under the 
prin ^al Acts'^or any of them," will enable us to keep the freedom which we 
h^ in the matter oJ floors and the interior work of buildings generally. 

I am stronglv of opinion that it is a mistake to throw upon public officers 
duties which th'; cannot effectively perform, or to make l---hich cannot 
b nforced. We might insist upon the most carefully - -^^^f .-^^^^J^ ^^ 
drawings but that would give no real assurance of the safety of the structure. 
This must always depend very largely on the quality of the .ngredients, then 
proLradmixtu;e, and accurate use, which can only be secured by the employ- 
men^ of skilled workmen and by constant supervision, such as no public of^cer 
ZT.We The real safeguard lies in the responsibility of the builder, architect, 
and o;^^er, and anything which would weaken that responsibility is to be 
deprecated. 

234 



l&'S?J'a"L'^T{.^^J Ri^CULATIOXS FOR REINFORCED CONCRETE. 

Kvon if there were general agree'iiieiit on all points, it would be a mistake 
to formulate bylaws in much detail. For instance, a few years ago, when the 
joint Committee of the Royal Institute of British Architects was engaged on 
the report, the system of strengthening columns by lateral binding or helical 
reinforcement was not in general use, though warmly advocated by a few men. 
In the report the stresses in pillars were assumed to be borne by the concrete 
and the longitudinal reinforcement, and no proposals were formulated for the 
extra strength given by the lateral binding. During the two years which have 
elap.scd since the publication of that report the use of helical reinforcement or 
lateral binding has become the more usual method. If the Council had adopted 
the Joint Committee's report as the basis for its rules and gone into the same 
detail, enacting the suggestions therein as regulations, we should probably 
now be unable to use helically reinforced columns until the L.C.C. regulation 
could be altered. During the debates before referred to it was said by the 
nflicers of the Council that there was the greatest dilliculty in making altera- 
tions in the Council rules. 

The Hritish Committee on Reinforced Concrete is at present sitting to 
enquire whether any amendment or revision of its report is desirable; but 
that Committee can readily alter for cause shown. Not so the London County 
Council, and it behoves us to be very careful in agreeing to anything. We 
must see, if possible, that there is some ready means of altering when occasion 
arises. 

It is also to be hoped that no excessive lire protection is required. 
In the clauses of the " General Powers Bill of 1909 " relating to steel con- 
struction, all steel girders and pillars in the exterior part^ of buildings are 
specified to be covered with at least 4 inches of fire-resisting material, but 
the casing to the under side and to the flanges may be made two inches thick, 
this section not applying to the case of buildings not more than 25 ft. in height. 
.Ml other pillars and girders, except subsidiary joists, are to have a similar 
casing of 2-inch thickness. A girder is defined in section 21 as "a metal girder 
or joist," but what a "subsidiary" joist is is left to be argued with the 
District Sur\eyor. In reinforced concrete work the metal is less liable to 
injury by fire, as it is not in large masses, but distributed through the concrete, 
so that a less cover will give the same protection. 

One can readily understand that a small round rod, of which only one 
point is within one inch of the external face, has a more efficient protection 
than a flange of a girder at a greater distance back. For the flange may be 
any width, from 3 to 18 inches, and the stripping of a small part of the 
covering leaves probably the whole width of flange exposed. Then in a girder 
or joist, except in the case of small floor joists, there is often an air space 
round the web, metallic lathing being used as a base for the fire-proof covering. 
In such a case there is greater conductivity, and the eiTect of a local heat is not 
so much confined to the part exposed. It must be remembered that any regu- 
lations for covering the steel with concrete define the minimum, and for many 
buildings the fire risk is slight. 

There is also the question of testing the structure or the materials. It 



WILLIAM DUNN. [CQNCBETEJ 

might prove a most serious burden to builders if the District Surveyor is given 
the power to require the builder to make any tests which the surveyor considers 
necessary. Under that part of the 1909 Act dealing with steel skeleton con- 
struction, as originally drafted, the surveyor had power, not only to drill pillars, 
but " to cause to be made any other tests he may consider necessary." Under 
the Act as passed this has been so rearranged that the making of tests appears 
to be confined to the quality of the materials. If the District Surveyor were 
empowered to require the builder to load up floors, roofs or pillars, in order to 
satisfy himself of the strength of the structure, the cost might be ruinous. 
The writer has not met a District Surveyor who would use this power oppres- 
sively in a wilful manner, but it might be used oppressiveh from sheer nervous- 
ness, want of confidence, or fear of responsibility. 

Presumably the Council will also require that plans, sections, details and 
copies of calculations in full detail be submitted to it, it may be in duplicate, 
on tracing linen, traced on the dull side of the paper, and so on. The amount 
(if drawings to be submitted to the Council, the District Surveyor, and others, 
is considerable at present. For instance, if it is a question of a reinforced 
concrete warehouse, there will be the special application with full details and 
calculations ; there will be another set for approval of means of escape in case 
of fire ; there must be plans for the local authority, showing the drainage 
scheme, for their approval; there m^y be plans for variation in the cubical 
extent or for variation in the size of the openings in party wall, or for altera- 
tion in the line of frontage, or for approval of plans by the freeholder. The 
County Council may, in one capacity, gravely inform us, under the hand of its 
superintending architect, that it approves the plans, and immediately there- 
after, in another capacity, by the same hand, inform us that the plans are not 
approved ! E\ ery obstacle of this kind affects most seriously the cost of 
building, by reason not only of the expense in preparing so many drawings, 
but also by the serious delays which take place in obtaining the approval of 
the Council. A delay in building entails loss of interest on the value of the 
site, which in London is an important part of the outlay. 

To the architect or engineer the preparation of all these applications 
requiring their labour brings more work and more fees, but it is the unfortunate 
person who builds and the unfortunate ratepayer who pays for the staff of 
officials, busily engaged in saying " Don't," who are to be pitied. It is the 
citizens of London who suffer by over-legislation such as I know of in no other 
city, but, unhappily, they never hea~ of Building .'\cts or bylaws until they 
proceed to build, and learn with astonishment that in the eye of the law the 
man who wishes to build is fall ol wicked Instincts, requiring very special 
repressive treatment. 



236 



-HMfJNI:-t.UlN<. ^J 



REINFORCED CONCRETE COKE BUNKER. 



^^ 



_^,^;.,^,.h^H Ji, /,--i.r'iv 



—■ic 



,)g/^X^>/|/4 REINFORCED CONCRETE 

COKE BUNKER 






, ^' /"'>'""'' 'o-*' •>*'' '" «'■"' ■/^/J«M parlicuUrs ana dra-wlngs of a Urgt Coke Bunker 
al Dunfermline, executed In Reinforced Concrete, as It shows -very clearly how practical this 
material ,s for such work The drawings were put al our disposal ty Ihe consulting Engineers- 
Messrs. F. A. Macdonald » Partners, of Glasgow. -ED. 



liiKKL has ruc,rml\ hv,n <-,cclcii lor the Dunlcnnhnc Cia.s Commissioners, at 
their gas works, Dunfermline, a large reinforced concrete coke bunker, which 
presents some unique features in constructional work, and particulars of the 
design of which we arc enabled to give by the courtcsv of the consulting 
engineers. 

The intention of the Commissioners, in the first instance, was to have 
used steel columns and steel longitudinal girders, but on the suggestion of the 
c.nsulting engineers this was departed from and a monolithic reinforced con- 
crete structure adopted. 

The bunker has been constructed over two lines of railway sidings, the one 
passing directly beneath the bunker being used for discharging into a receivin<. 
bunker below ground level, and also for loading into railwav truck from the 
large reinforced concrete bunker above, and the other, passing bellow the outer 
reinforced coPcrete cantilevers, being used for ordinary siding purposes, and 
also for loading purposes from the reinforced concrete bunker. 

While traffic was suspended for some short time, during the construction 
ol the bunker, on the railway siding immediately beneath it, the outer railway 
iHic had to be kept clear for trafllc during the whole period that constructional 
operations were in progress, thus adding materially to the practical difficulties 
01 the work. 

This difficulty was, however, overcome by the special method of dealing 
vMth the centering, as suggested by the consulting engineers and successfully 
carried into operation by the contractors. 

At the top of the bunker, and supported by the large reinforced concrete 
stay beams shown in Fig. 9, there has been constructed a receiving hopper 
and also a remforced concrete bottom for another storage hopper for breeze 
and the total weight of contained material, on which calculations for the design 
of the structure were based by the consulting engineers, was 350 tons of coke 
.n the large bunker and 40 tons of breeze in the breeze hopper, in all 390 tons 
o\er and above the self-weight of the structure. 



*37 



REINFORCED CONCRETE COKE BUNKER. [CONCKb:i tj 




F:g. 1.-Pl*n »Nn Sections of Hoppe 



238 



>-EJN(ilNLF,tflN( 



"^ RI-INFORCRD CONCRI-TE COKH IWM<I-Ii. 

I., addition to tiicsc loads, it u ,11 be observed from the ^^encral drawings 
.l>at rc.ntorccd concrete brackHs bav. been constrticted, monolithic with the 
mam btmker wa Is, to carry the loads arising from the roof principals an.i 
roof girders of the adjoining buildings. 

The (Ok. is fed into the bunker by means of a revolving screen, erected 
on a pla lor,n adjon.ng ,he ,nain bunker at sunnnit level, which platform 
pa.tly oblan.s support on tin- reinforced concrete structure. 

To enable the <oke to be dropped from this revolving screen into .he nu.in 
bunker w.thout bc.ng br<,ken, and also to form a support for the end of the coke 
screen, a re.nforced concrete structure has been constructed within the main 
bunker, compr.smg lour reinforced concrete columns, braced together with 
diagonals and supporting a series of inclined and graduated reinforced concrete 




slabs, each slab so formed as to be slightly concave on its upper surface, and 
down which senes of slabs the coke will llow, eventually heaping up within the 
storage bunker at its natural angle of repose. 

At the summit of the main structure, as mentioned, there has been con- 
s ructed a receiving hopper. This hopper has four openings, fitted with hinged 
steel plates. These hinged plates will be kept closed until the coke in the 
main bunker reaches to the level of the slide doors, when thev will be released 
thus enabling the bunker to become completely filled. 

Inclined reinforced concrete beams have been introduced in the desi^^n for 
he purpose of staying the summit of the structure. It will also be noted that 
the space between two of the large arched stay beams has been filled in on 



239 



REINFORCED CONCRETE COKE BUNKER. 



[CQNCBE:iIiJ 



one side with a reinforced concrete slal), thus formins^- the bottom of the breeze 

hopper. . , . 

The whole arrangement is one of particular efficiency and in-enuity and is 
shown on the drawings accompanying this article. 

it will be noted that the position of the main columns in the transverse 
direction is limited by the presence of the railway sidings, which existed prior 
to the construction of the bunker, and this also necessitated the cant.levermg 
out of two sides of the bunker beyond the columns as shown, thus com- 
plicating the problem of design. 




The reinforced concrete columns on the one side are 12 in. by 12 in. 
section and are supported on reinforced concrete bases, the loads from which 
are again spread by means of a special beam along the length of an existing 
masonry wall, constructed as a retaining wall and having a minimum breadth 
at top of 2 ft. 6 in. 



240 



^ 



, CiONSTBlKtiaNAlJ 
EN(ilNHj<IN<, — J 



RHIS'FORCFn CONCRETE COKE BUNKER. 



On the other side the breadth of the supporting,' rohunns was necessarily 
limited on arcoiuit of llie Hoard of Trade res^adalions for clearance of railway 
Irallic, and tlic seel ion adopted was u in. 1)\ 9 in. 

On this side also the loads from the columns are received on reinforced 
concrete bases, and the loads ayain spread by means of a special beam. 

The j,Moniul under this line of columns was found to be of the nature of 
" forced " material foi .-i considerable depth, and this difliculty was dealt with 
by excavatin},' a broad trench down to the bardj the trench beings timbered in 
the usual manner, and after llu excavation was complete the trench was filled 
up solid with lime concrete, thus practically forming,'- a continuous wall. 

Above this wall of lime concrete the special beam already mentioned was 
constructed, and after completion of this foundation beam the construction of 
the column bases and < olumns uas proceeded with. 




Figs. Nos. 3 and .). show the method of reinforcing the bottom of the 
bunker, which is 9 in. in thickness, and supported on the main reinforced con- 
crete cantilever beams running transverselv, and on the reinforced concrete 
T beams Bi running longitudinallv. 

The method adopted by the consulting engineers of reinforcing the bottom 
of the bunker, which has an enormous load to carry per square foot of area, is 
exceedingly interesting. 

Details of the large cantilever girders .\ are reproduced, both in elevation 



2+' 



REINFORCED CONCRETE COKE BUNKER. 



[CONCRETE] 




and cross section, sec 
Fig. 2. 

These girders at their 
maximum section are 6 ft. 
in hcig-ht, and the disposi- 
tion of the reinforcement 
shows clearly the very 
effective character of the 
reinforcement in connecting 
the axes of tension and 
compression throug-hout 
the web of these enormous 
girders. 

It will also be noted that 
these girders, in addition to 
the load arising from the 
contained coke, have also 
to carry the deadweight of 
each outer side wall at the 
extreme end of the canti- 
lever. 

The main reinforced 
concrete girders. A, are 
braced top and bottom by 
reinforced concrete beams 
at right angles thereto; 
at bottom by beams, Bi, 
which in addition to being 
calculated and designed as 
beams, are also further 
reinforced as struts and 
ties; and at top, by struts 
C, which are designed and 
reinforced as struts and 
ties. 

It will also be observed 
that certain of the reinforc- 
ing bars of beams, B and 
C, are hooked round the 
buttresses, D, of the end 
walls, the section of such 
bars being calculated to 
enable them to act also as 
ties, as well as struts. 

The outer walls of the 
bunker, resisting the thrust 
of the contained coke, are 



2 + 2 



[j», OON.vrPUC-| lONAl.l 
LtVENtilNLLKINl. —J 



REINFORCED CONCRETE CORE BUNRER. 





■ { 


i 


;/.: 

J 






\ 


b 


^7 

iV- 




* 




a 


" 







; 


T" 










x^ 


i 

c. 


^'^Y 




1 




\^- 




\ ^ 




\' 


LK \ ILl 






- 





T 




•9H 



f) in. in thickness, and their 
span in the horizontal direc- 
tion is lessened by the intro- 
duction of buttresses or 
vertical beams, D, details 
of the reinforcement of 
which we reproduce in 
/•'i.iT-*- 5 and (). 

These vertical beams, 
D, are held at bottom by 
the tie beams, C, as men- 
tioned, and at top are re- 
ceived into beams, E, 
which are a5,'ain held by the 
beams, P. 

VVe also reproduce 
details (/<"/>. 9) of the 
large arched stays, N, at 
the summit of the struc- 
ture, showinj;^ the effective 
trellised girder arrange- 
ment of the reinforcement, 
and these arched stays are 
again strutted in the other 
direction , by the inclined 
beam, O, springing from 
beams, E, to the summit 
of the arched stays. 

For the formation of 
the bottom of the breeze 
hopper, an intermediate in- 
clined beam, M, has been 
introduced between the 
arched stays, as shown by 
Fig. 9. 

The internal structure 
lor ensuring the downward 
gradual flow of the coke 
into the bunker is of itself 
an exceedingly interesting 
and somewhat intricate con- 
struction, and the general 
formation of same is shown 
in Fig. I. It will be 
noticed that the whole of 
this internal structure is 



U3 



REINFORCED CONCRETE COKE BUNKER. 



lOQNCBEl'a 



e..ned on the subsidiary independent bean., H, which are, again, supported by 
the arched stays, N. 




,„, L. ,,.d ..c --»--;':,;:-:: rapport ,.» .^ving .,oppe, 

the tie beams, i, V, ana 

at summit. _ ^^ ^^^^;^^ ^he indined slabs, S, and 



244 



[y.lON.vrUIK-nONAl.l 
L'v tNdlNL.! IMNti — J 



REINI'ORCED COXCRHTI-: COKE HUNKER 




REINFORCED CONCRETE COKE BUNKER. 



ICDNCBETEl 



the f<,rmati(,n bcin- as shown in the detail thereof, and the coke flows down 
this series of inclined slabs in such manner that it is not broken ni its descent, 
and finally spreads out to its natural angle of repose in the mam storage 
bunker. 

The general arrangement of the bunker was carried out to the instructions 
of Mr. .Uexander Waddell, manager of Dunfermline Gas Works. 

The contractors for the reinforced concrete work were Messrs. John Ellis 




& Sons, Ltd., and the steel reinforcement was supplied by The Trussed 
Concrete Stee! Co., Ltd. 

The cement used was the J. B. White brand of Portland cement and was 
supplied bv The .\ssoclated Portland Cement Manufacturers (1900), Ltd. 

The work was carried out to working detail drawings prepared by the 
consulting engineers, Messrs. F. -V Macdonald and Partners, 135 \^ elhngton 
Street Glasgow, who also supervised the work during erection, and to whom 
we ar^ indebted for the loan of the complete set of working deta.l drawmgs 
from which we have reproduced our illustrations. 

We mav add that the complete working detail drawings sho^y clearly the 
intricacv of 'this particular work, and the highly emdent design of the remforce- 
ment adopted by the consulting engineers. 



246 



j/.tDN.TrPUlTKlNAI.I 



RHISFORCED COXCRETE COKE IWXKEl 




" -■-^'■^-" iit% ' '"laf ' 



Reisi ORCED Concrete Co::e Bun 



2 + 7 



REINFORCED CONCRETE. 



[CDNCBETEJ 




= =- — = =^ 

THE CALCULATION OF 
CONTINUOUS BOWSTRING 
GIRDERS, AND ITS APPLL 
CATION TO A REINFORCED 
CONCRETE VIADUCT. 



1 



The present jrl.cle ,s a IransUt.on of J pampl.Ut -wriflen ty Mr. H. Lossier, and deals 
■unth the case of a conluwoas tolvstr,ng viaduct designed by Messrs. Considere. Pelnard & 
Lossier, and -which has teen adopted by the Orleans Rail-way. Messrs. Considere have 
kindly placed the information at our disposal. ~ED. 



A,.,„oron Uk- computation of con.i.uun,. b.a n- ha> n.nv become a common prat^. 
the treatment of continuous arcliecl structures lias, owing to the complexity of the 
theory involved, remained almost untouched. This type of structure however, assunies 
importance in lar^^e constructions, as it permits an economical d.strtbulton of the 
material and a large margin of safety. , , . , 

The author has shown, in previous publications, that continuous .arched structure 
may be computed in a simple manner bv nu-ans of the eUipse of elasticity.^ The present 
else is that of a continuous bowstring viaduct, ^^ithout diagonals, the design o Which, 
bv Messrs. Considere, Pelnard .'t Lossier. has just been adopted by the Orleans Railway 
for Contr.-is (Gironde), as the result of a competition. 

The viaduct consists, as shown in I'lgs. i 
and 2, of a platform ya metres (23 ft. 7 in.) wide 
between the parapets, carried by two main gir- 
ders of five spans, namely, a central span of 
40 m. (131 ft.), two intermediate spans, each 
of 31 m. (toi ft. 6 in.), and two terminal spans, 
each of q m. (30 ft. 6 in.), giving a total length 
of 120 m. (3q5 ft.). Each girder in the central 
spans is composed of an upper parabolic member 
and a straight lower member, united by vertical 
members, whilst the terminal spans are simply 
prolongations of the low-er member. 

Considered in itself, each of the central spans 
is a bowstring without diagonals. In this struc- 
ture, the vertical members, being hinged at the 
ends unlv transmit vertical stresses, and cannot be considered as replacing the diagonals. 
We mav'assume without serious error that corresponding points on the ui^per and lower 
members are equally displaced vertically, and therefore jointly resist the bending 
stresses Each girder mav be regarded as a continuous arched structure of three 
soans the two ends being each prolonged by a horizontal beam, freely supported at the 
end without breach of "continuity (Fi.^. 3)- The computation of such a system .s 
.^reatlv simplified bv the emplovment of the graphical method, due in the first place to 
Prof W Ritter, and based on 'the theory of the ellipse of elasticity. (See H. Lossier. 
'• Cenerd Theorv of the Continuous Elastic .\rch on Rigid Supports," Pans, 1903). 




Seci 



248 



f J, CONSIDUCTIONAU 
[ft. ENOtro iJ^lNr. — J 



CONTINUOUS HOWSTIilXG CfRDHRS 




I he ellipse „f elasiidty .,1 ,|„. |,„i,u H (/•Vt;. ^ is determined bv 
laking into .urount ihe f.Kl il,.,i ih,. plane hi, cannot undergo a 
in,.viinent of translation, and that the centre of rotation coincides with 
H. Ihe -elastic weight " of the ellipse, G b, is found hv assuming 
thai the beam AH is lixed at B and free at A, and that' the elastic 
weight of its ellipse is C.^. If a vertical force P ads at Ihe free end A 
the vertical displacement at A is 

A /, = I>G, -' H 

2 
wlu'n- /, is the length of AH an.l i, Ihe distance from A to the antipole 
N of il„. Inree P nlaliv.ly to (;,. The angle through which AB must 
lie lurned lo annul llil> displacemenl isot = -_ 



Now, 



or, 



A/; 
of = , = P/i G„ 



Gr — Gi 



'21, 




hi or.ler K, .Iclermine (l,, graphically, a vertical is drawn proportioned 
to (!,, at a dislance /, from B, and a vertical droj.ped from N gives 
Ihe \alLie rct|uired. 
^ l-"or simil.ir reasons, the ellipse of elasticity at C is reduced to a 

5 point coinciding with C. Assuming the svstem ABC to l)e free, we 
§ hnd the ellipse of elasticity C , of the point C. The elastic weight 
> Gc i>^ fui""l l'> a construction similar to that previouslv adopted. 
= As C is llxe;!, the ellipses C.'., and G^ must le.-.d to the same value 
2 for Ihe rol;ilion of C,, or 

t Hi'., G', = K,e Gc 

- r', and r^ heiiig the respective distances of G', and G(- from the 

^; straight line />•/,-. Then 

^ Gc = G'., '"'•^ 

/"c 
Ihe eUipses al the points I) and E are determined in a similar 
nianiier. The structure being symmetrical, it is unnecessarv to per- 
lonii a series of operations in the reverse direction, starting' from F. 
In each span, two classes of stresses have to be considered, (i) 
those due to loads .icting directly on the span in question, and (2) 
those due to loads acting on other spans and tr.insmitted hv the 
adjoining sp;ins. 

(1) The tliree middle spans m;iy be regarded as simple arches fixed 
at tile exiremiiies on el.istic supports. Such an arch may also be 
regarded as a simple arch with fixed extremities on fixed supports, 
infinitely small elastic elements intervening, the deformations of which 
coincide with the movements of the supports. These fictitious elements 
h.ive as ellipses of elasticity those of the supports themselves. The 
middle spans, therefore, have the following ellipses of fixing : 
Span BC— At B, ellipse Gb : and at C, ellipse G'c. 
.. CD- „ C, .. Gc; .. D, ,. G'l,. 
.. DE- .. D, ., Gd: ,. E, „ Ge- 
Combining the ellipses of elasticity of the different elements of each 

2+9 



REINFORCED CONCRETE. 



[CONCREllLj 




span bv the nu'thod of lunicular polyt<oiis, taking into 
acciiuni llif sii|)pi)rts, we obtain llie surfaces of in- 
lluence of tlie components of tlie reactions at the junc- 
tions. 'I'liese surfaces enable us to determine, as 
shown in /•"I'.t;. 3. the lines of intersection and the en- 
velopes of the reactions, as for arches of the ordinary 
type. Tlie central .arch, treated in this way, is 
symmetrical, wliilsl the two adjoining arches are 
asymmetrical, and liave been so treated. 

(2) Any force R, , acting on the extremity C of a 
svstem ABC, through the intermediary of the adjacent 
span CD (/■'/.;•• j>), is balanced by two reactions : the 
reaction \'i of the support and reaction Hj of the 
svstem ABC. These reactions must satisfy certain 
conditions which enable them to be determined without 
ambiguity. The support of C being hinged, the reac- 
tion Vi must pass through the point C, which must 
also coincide with the centre of rotation relative to the 
reaction Hi. I"or this condition to be realised, Hj 
must .act .along the antipolar kk. and the resolution 
of Ri into \'i and H, is thus completely determined. 
The action of II 1 on the span .\B is determined by 
the fact that the reaction at A is vertical, owing to 
the expansion devic 
the hinge. 

Imagine, in !■ i 
tr.al sp.m CI); thi 
others, R, and R.j 



whilst that at B passes through 

\. a force P acting on the cen- 
force mav be resolved into two 
tangential to the envelope and 
cutting the line of ;iction of the force V on the line of 
intersection of the reactions of the span CD. Eac'i 
of these fcn'ces R, and R., may then be resolved into 
two forces Hj_„and \\_,,, the one acting on the 
.uljacent sp.an, tlie other en the hinge of the adjoining 
support. Each force H,_., may be again resolved into 
a vertical reaction at the end supports, and an oblique 
reaction passing through the hinge 3 or E. 

Should the force P have the position P„, so that 
the reaction \'i passes through the hinge C, the 
thrust Hj is zero, and the action of P„ on the system 
.\HC is zero, consequently all the lines of influence 
of tlie moments of flexion of sections of this system 
will cut the .axis of .abscissce at the ordinate of the 
force Po- 

The author has also determined graphically the 
surfaces of influence of the bending moments of 
different sections of the central span CD, and also the 
most unfavourable positions of loads, as regards the 
bending moments, \\hilst, in ordinary continuous 
beams,"^ the most unfavourable loads generally affect 
whole spans separated by spans free from load, in the 
system considered the three middle spans are always 
loaded, but only over a portion of tlieir length. The 



I J. CONMBlKTlONAl.l 
l'^ HN(;lNt.F,BlN(i ^j 



COXTIXUOUS fiOWSTh'/XG GIRD/iRS. 



ordin.iiv beams, and are 



terminal span-,, en llic ,,i|„-r h.nul, .are lo be regarde 

Ihen lore eillvr eoniplelelv free „r eompletelv loaded. 

Tin. enns,rue,i„n „f a further diagram nf the maximum bending' moments under 

he n,os, un avoural e d.stnbut.on of lo.nds leads to the conclusion that, bv assuming 
1.. he whole sp..,n ,he v.akte of the n,axinu„n ntontent, treating the span as hinged 
■n II.'- lun.lH.ns, stresses are arrived .-,1 which .are too high at the crown 
I'ut loo low a, .he springing of the arch. High values, .and conscMuentlv satisfactory as 

e,..rds s^ength. ,f n<,t as regards economy, are therefore obtained bv assuming no 
hx.ng at the juncfons or sections at the crown and ribs, and perfect fixing for secHons 
near the sprtng.ng. I h,s conclusion nu.st not be tnade a general one, for if the span 

I;::: -o^Ziaier' '""^^ ""'- '-"^ '- ^"'^-'"' - ---^ -^^•>- - -: of 

A fur.her^ graphical construction pertnits the calculation of the load required to 
pnviuce :. g.ven ver.tcal .hsplace,„e„, „f ;, support. 1, is found th.a,. in or<ler to reach 




ocn 7si 7" " , ;*' ^'^■•^'. '■'■"^'"■•-"••■^'- - ^•''■■'i-al displacement of no less than 
- o c, ,. (8 n.) would be recpnred. This is unlikely ,o be attained. The tvpe of con- 

~ "^h":'1 '" '"^ r^""' ''"''''' ■■' '^^'•^^ '' "^-'''"'>- -'--^ - ccLider ; h- 

in excess of that of most other svstenis. 

It now rem.ains to be shown that the discrep.ancies between the theoretical values 
•mi hose actually reahsed are not greater than in the more usual tvpes of structure 
i Ho?, ■'''k rV"^"^ exatnination are: (t) that the linear "variations of the 

.nter,or timbers and of the vertical connecting metribers are ne^digible ; h) that the 
.upenor and tnferior members satisfy the ,he>,ry of elastic deformations. 

So far as the lower metBbers are concertu.d, the combined action of the dead load 
...td of the surcharge producng the ntaxinu.m bending moment in the central span 

nto' ::rt t"T","\ "'^^ l""""""-^ ^^ "^^'^^- ''^'''"- "^^ ^-^=°" ^^ ^^e conc;i ; 

account, ,t ,s found that the actual stresses produced (tension in the lower and con,. 



REINFORCED CONCRETE. [CONCRETE] 

nression in the upper members) are about 13 per cent, of the total calculated stresses. 
.\ similar calculation shows that the eloni^ation of the vertical mejiibers, also taken as 
being 0-3 millimetres per metre, produces stresses which are less than 2 per cent, of the 
total stresses. Together, it may be said that the elongation of the lower horizontal and 
vertical members increases the calculated stresses by 15 per cent. The secondary stresses 
in steel constructions, due to the rigidity of the junctions, have a similar value, and it is 
therefore legitimate to neglect the influence of such elongations in continuous bowstring 
girders, as is done in dealing with steel structures. 

The superior members are subject to complex bending and resist only compressive 
stresses. They consequentlv behave as arches, the deformations of which correspond, 
within the permissible limits, with the theory of elasticity, as was proved by the 
experiments of the .Xustrian engineers in 1895. 

Experiments bv the French Reinforced Concrete Commission have proved that, as 
soon as the elongation of concrete exceeds by o-i to 0-2 mm. per meire that which it could 
resist without rupture if it were not reinforced, its co-efl'icient of elasticity diminishes 
rapidlv and soon becomes practically zero. Now, the concrete of the inferior members 
is subjected to an initial elongation of about 0-3 mm. per metre produced by 
the dead and live load; this concrete therefore behaves in some respects as 
a plastic substance under the bending stresses acting on the horizontal members. 
Under such conditions, practically the whole effective moment of inertia of the members 
is furnished by the steel reinforcement, the [x-rcentage of which is relatively high. 
The theory of 'elasticitv is therefore applicable to them. It follows that the exactness 
with which a structure 'of this kind can be computed is similar to that of other reinforced 
concrete constructions. The application of the theory of elasticity, which was ex- 
perimentallv justified for arches by the investigations of the Austrian engineers m 
1895, and for continuous beams, suitably reinforced, by those of Messrs. Wayss & 
Freytag, appears to be equally admissible in the case here considered. 

Conclusions.-U is not possible to draw conclusions of a general nature from the 
studv of this particular case. The onlv abject of this paper is to show the remarkable 
simplicity with which the ellipse of elasticity permits the solution of apparently very 
complex hv[>erstatic svstems. 

In spite of the incontestable advantages of the so-called exact methods of computa- 
tion it would be an exaggeration to condemn a priori all the simplified methods which 
lead' to a less rationaldistribution of the general stresses. In fact, in an isostatic 
structure, the stress in anv member is independent of its stifTness and of its resistance; 
should the latter be insufficient, rupture occurs, whatever may be the strength of the 
other portions of the structure. In a hyperstatic structure, on the other hand, the 
distribution of the general stresses is determined by the deformations of the different 
elements If one of these begins to vield from lack of resistance, the load, or a part 
of it is taken bv the stronger members, and if the latter can resist the additional 
stresses thus proiluced, rupture mav be avoided. This is what occurs in reinforced 
concrete beams, the continuity of which is imperfect over the supports, and the stability 
of which is nevertheless assured bv the resistance of the other paits. 

Ho-vever such a redistribution of stresses cannot occur, in general, without the 
structure suffering injuries which more or less affect its good appearance and its 
durability. The sc^called exact methods of computation will therefore always have 
the advantage, in comparison with the approximate methods, of leading to a more 
rational disposition of material, and of allowing the strength of each member to be 
better proportioned to the stresses it is to support. 



252 






ilM-t IJlMi — J 



TESTS- 




TESTS ON REINFORCED 

CONCRETE CONDUCTED 

IN GREAT BRITAIN. 

iPART VII. I 



F,f^ t!, 1 f i, i^" "^J'"^ *'"'" JPP<r^redln our Mjy, SepUmbcr, November, Unuir). 
Ftbruarn ind Mirch numbers respectt-vtly. The following pjrilculjrs of lesls /re n^ 
presented, ind further jrHclesiPlll appear from lime to time. ~ED 



A SPIRAL COLUMN. 

t..,.T,' '^^'i!"''"' ?"","' '' '^•'•»--\- ""h tl"- co-operation of Messrs. W. Cubitt & Co., ha, made and 
tested two hooped cohimns such as reroinmended bv M. Considere 

The columns were of oct.ison.-il section of the dinK.nsi..ris shown {Fig. 38), and io:ft. in height. 



JW 










;^T-^n" 


i-\\\\\ \ 






1 


— 


T— 


■j- 


.^ 


T 


J/* 




























/ 




J^f 


JM 
























, 


^ 






' 


IM 






















^ 












i*0 












^ 


^ 














g'O 








^ 
























' 


'II! 
















' 


























, 


J i - 


, 








'1 






Zfe 






1 














1 






fro 


















'— r 




la M 


/at 






















fo 
















. 






/ec 
















■ - 




"" 


no 
















"/ 






" 






/V.MH 


/6l> 
















-J 


^ 


■" 


- 






/JO 
















/ 


^^ \- 






~ 




aotoa 


/fo 


_ 














/ 




1 
















~ 








/JD 


_ 










_ / 




T 


























" 




/io 


_ 










ij 




/ 






























^trn 


M 










7 


/ 




/ 


























1 


m.Ms 


/oo 










'i 






T 






















1 


9a 








/ 


1 




/ 












~^ 


' 








"""' 


eo 








/ 






/ 










^ 






~ 






7a 






I 


I. 




/ 




~^ 








" 




i 


~ 




Ta-aae 


eo 




-4 


7 




1 
























~ 






SD 




J 


/ 




/ 


























"" 


~ 




4^ 




4. 




/ 






















~ 


~ 




~ 


~ 




JUJMV 


JW 


1 




/ 






























~ 


~ 


1 




« 
































~ 


~ 


■~ 


~ 


1 




/f 




































~ 


~ 


1 






J 


-i 


-J. 


_1 


_ 


— 




























. i \ 


"""" 



J^eOuctio/? /n /e/r^/Jt m i/rcAes 



253 



TESTS. 



ICQNCBETEl 




The reinforcement of the first column tested consisted of eight vertical 
wire^ J in. diameter extending: for the full height of the column. 
These were bound round spirally with J-in. wire, the length of the 
wire employed for the spiral being 227 ft. The volume of longi- 
tudinals was therefore 042 per cent, and that of the spirals 0-30 per 
cent, of the total \'olume of the concrete. The wire was first wound 
closely round a drum, and was then allowed to spring out to the exact 
pitch of i] in., being -.h^ of the diameter of the spiral (M. Considere 
recommends one-seventh to one-tenth), the wireworker having nn 
difiRculty in arranging this. Both sets of wire were of mild steel, and 
the verticals and spirals were bound together with fine wire at the Fi«. 3S. 

crossings to keep them in position while the column was moulded. The diameter of the spiral 
was gi in. The moulding was done vertically, in 6-in. layers, and rammed with a wooden rammer 
8 in. in diameter. 

The concrete was mixed in the proportions of i of Portland cement to 2 of I.eighton Buzzard 
sand, and 2J of pea shingle, or about Q70 lb. of Portland cement to -083 cu. yd. of sand and i cu. yd. 
of shingle. 

The column was kept in tlic mould for five days, and was then removed and stored in wet saw- 
dust for a further period of 56 days. It w.is then tested horizontally in a machine by Messrs. 
Kirkaldy, an endeavour being made to counteract the effect of the bending due to its own weight 
by a weight equal to half the weight of the column, acting upwards at the centre. The second column 
was made and tested at a later date and in the same manner. In this case, however, while the 
.dimensions of the column were kept the same, the sizes of the reinforcements were increased, the 
spirals being 0-21 in. and the 
longitudinals J in. diameter. The 
spacing of the spirals w-as again 
li in. The volume of the longi- 
tudinals was 100 per cent., and 
that of the spirals 065 per cent . 

of the total volume of the column. t^ 

When the column was tested the 
portion of the former column 
which had failed was cut away and 
the shortened column re-tested. 

The gradual shortening of the 
columns under an increasing load 
is show-n in the diagram [Fig. 37), 
the se\"eral columns being marked 
A, B, and C, the latter being .\ as 
re-tested, the stresses being those 
per square foot of section within 
the spiral windin.gs. The portion 
outside, not being rein.'cced, does 
not add materially to the resist- 
ance, and is only necessary as a 
protective coating. This diagram 
shows that for Column A, as in the 
case of M. Considere's tests, there 
is a great shortening at first under 
light load due to the particles 
taking a permanent set amongst 
themselves and to the concrete 
taking up its be.iring against the 
spirals. The proportion of the 
volumes of the reinforcements with 
respect to the total volume of the 
concrete was ©'0042 and 001 for 
the longitudinals, and 0^0030 and 
o'oo63 for the spiral in Columns .\ 
or C and Column B respectively. 

At about 7S0 lb. persq. in. on 
Colunm .\ the shortenings became 




= 54 



t-NOINt-LKINli — J 



Ti-srs 



regular — ; <■., the stress ami strain were proportionate. This continued up to about 2,020 lb. per 
sq. in., when the outer casing of the concrete outside the spirals bcRan to crack. (It will be 
noticed that this is about the resistance under direct compression for concrete not reinforced.) 
The shortening then increased more rapidly than the load. When failure occurred, at 2,815 "'• 
per sq. in., it was local and near one end where the outer casing flaked off (vide, Fins. 39 and 40). 
The spiral wire broke in two places, showing the characteristic reduction of area at the point of 
fracture, and the longitudiii.-il wires bulged outwards at the point of fracture. The concrete at 




\ (rk-testei>). 



this place proved e.xceedmgly friable, and easily rubbed ott with the fingers. The sand seemed to 
be not as sharp as required in the best concrete work. 

The failures of these columns were gradual, and even after the failure the two portions of the 
first column were sufficiently held together by the eight longitudinal wires to permit of the column 
being slung out of the machine as one piece by means of a rope sling round its centre. Figs. 39 and 
40 show viesvs of the colunuis after failure. The columns were made by men having no special 
experience in reinforced concrete construction, and under no specially skilled supervision. 



TESTS. 



ICQNCBETEl 



BEAMS BY MESSRS. W. CUBITT 6 CO. 

Some small test beams were m.ide by Me'isrs. \V. Cubitt & Co., and tested in their Amsler vertica 
press by Professor Unwin for the Royal Institute of British Architects' Joint Committee on 
Reinforced Concrete. The dimensions and arrangement of reinforrements are shown in F:g. 41. 



TABLE I. 



M.irk 
Be.ira 


Miximum 
Load 


Lo.id .It 
which the 
last dt- 
fiection 


Ultimate 
Deflection 


DtflfCtlOI, 

with 
S Tons 
"Load 


Set with 
6 Tons 
Load 


.\t l-i 


St Crack 


Nature of First Crack 










was taken 






Load 


Deflection 






Tons 


Tons 


In. 


In. 


In. 


Ton 5 


In. 




,^' 


6-.'o 


6-00 


o-ooo 


o-...ho 


— 


3-5 


0-037 


Diagonal cracks left of 
centre. 


A^ 


S-So 


s-oo 


0-040 


0-040 


— 


4-5 


0-0 ?5 


Diagonal cracks right of 
centre. 


A' 


ySn 


y.io 


0-060 


0-050 


— 


,5-0 


0-042 


Diagonal cracks left of 


B' 


<j-50 


8-00 


ffo6 ! 


0-029 


0-005 


8-0 


0-061 


Crack>. chieflv diagonal. 


B= 


lo-oo 


f)-oo 


o-ioo 


0-040 


0-008 


7-0 


0-060 


Diagonal crack right of 
centre. 


B' 


<,-20 


9-2.1 


0-488 


0-06S 


— 


S-5 


0-I26 


Diagonal cracks near ends 
and after at centre. 


C 


t6o 


0-5O 


o-MO 


0-040 


0-010 


6-5 


O'oS'j 


Diagonal cracks. 


C-' 


S-;o 


8-00 


o-o8,s 


0-042 


0-002 


5-0 


0-042 


Very snail cracks left of 
centre. 




g-50 


9-50 


o-o6o 


0-0S+ 


— 


7-0 


0-073 


CracKS near ends. 


D' 


6*00 


6- so 


o-oSo 


0-044 


0-020 


Vo 


0-036 


Small cracks left of centre. 




6-go 


6-90 


0-460 


0-058 


— 


5-5 


n-os6 


Two, nearly verticil. 


D< 


7-30 


'"■" 


0-660 


0-058 


0-0 !o 


5-^ 


0-o(io 


Nearly vertical. 




^^ ^^ ^' V^/a.r^^ 














6'o' 














r^ 




— 


n 

- — 






1 




1 6 


6' 











T 


\ 







































4^ 'e//a, rff4^ 



Fig. ^\. Dimensions and Ar 



256 



[TTcai 



THSTS. 



Table I. gives the results of the tests. The loading had bccncoiitinued con';icl<rably biyimd 
the time of failure before thc'photographsjwerejtaken, yet none of the beams showed any signs of 




Be 



Tested 



. 43. Bea 
R.I.B.A.' 



. pla 



Joi; 



collapsing. Shearing had a considerable effect in the failure of all the beams. Beam A failed las 
would be expected) entirely from diagonal tension, the shearing along the rods being clearly shown 



TESTS. 



ICONCBETEJ 



in the photograph. Th.e effect of diagonal tension is also vcrv evident in Beam B-, and the inlluence 
of shearing stresses is indicated by the inclination of the crack in Beam C The crushing at the 




Fi;!. 45. 
R.I.B..A..'s Joi: 



top of this beam did not occur until the bottom crack had opened considerably. The vertical crack 
in Beam D=* opened at one of the stirrups, and a wedge-shape piece dropped out at the bottom ; both 



E 



TESTS. 



tlie vertiial ntid inclined cracks in this licam nponcJ simultaneously 
liiains are samples, three beams of each class were tested. 



In the tests of which these 



Fig. 46. BcamC". 




Reinforced Concr 



^59 



TESTS. 



ICQNCBET F.] 




Fis. 49. Beam D% 
R.IB.A.'s Joint Committee 



260 



tTobec„ittiiuic<l.) 






•iALl 



POST OFFICE BUILDINGS. 




THE NEW MONEY 

ORDER OFFICES AT 

HOLLOWAY. 



W€ are jtjjiln giving pArllcuUrs of a Post Office Building erected In reinforced concrete 
under the supervision of H,M, Office of Works* the present example being the structure 
intended for the use of the Money Order Department at Mottowjy- We are noiv giving a 
preliminary article on the building in its early stages and ivltt later on publish one on the 
completed structure. - KD. 



I 111-: l>uilflini4 (Icstiilxd in this aiticlc, and wliuh is now in course of 
erection, is the latest of a siries of hirs^e huiithiii^s for tlie extension of I'ost 
Ollice facilities in I.oiuion. 

This \\<irk is heinjj erected under the instructions of }1.M. Oflice of 
Works, for uhiiii Sir Henry Tanner, I.S.O. , l-'.R. i. H.A. , acts as tiie principal 
architect. 

Till' entire construction, with tiie exception of tiie front wall elevation, 
is in reinforced concrete on the Coij;^net syst'jm and under the supervision of 
Mr. J. Rutherford, of H.M. OHice of Works. The contractors for the work are 
Messrs. W. Kint; &• Son, of London, who ha\e also executed the Western 
District Post Oriici- and the Lombard Street Mranch Post Ollice on the same 
system. 

The contract for this buildin;.;' was placed in open competition, and, after 
consideration of the tendeis and a very careful expert examinati<]n or the 
\aiious schemes proposed, the Ollice of Works decided to accept the one 
submitted by Messrs. Edmond Coitjnet, Ltd. 
The building;' is in the shape of an ]■'.. 
measures approximately J53 ft. and the width 
The three wings measure respective!}- : <SS ft. 
70 ft. by 42 ft. 

The building is to be composed of a basement, five reinforced concrete 
floors, and a Hat rot)f of the same material. The total height of the structure 
Irom the ground level to the roof will be approximatelv 85 ft. There 
will also be a certain niunber of mc-zzanlne llooi's throughout tiie height of the 
main body. .Mthough the front elevation is to be executed in brick and stone, 
the walls ol the wings are to be in reinforced concrete, of a thickness of 
5 in. onlv. 

The stairs and balconies of the building are to be entirely in reinforced 
concrete. The building is to be fitted with \entilating shafts, also of the 
same material. 

On the ground, situated at the back, a large boiler-house, entirely in 

u 261 



The total length of the front 
of the main body is about 50 ft. 
by 42 ft., loi ft. by 42 ft. and 



REINFORCED CONCRETE. 



[CONCBETEJ 



reinforced concrete, is also to be erected, tlie dimen- 
sions of which are approximately 47 ft. in length, 36 ft. 
in width and 26 ft. in height. This building will be 
partly buried in the ground. 

An underground passage in reinforced concrete will 
provide means of communication between the various 
wings of the building and the boiler-house. A water tank 
will also be erected close to the boiler-house. 

The contractors began the work on the 25th of 
October last, and we are presenting two photographs, 
taken recently, showing the progress of the work. 

The centering for the pillars, floors and walls under- 
neath the first floor, which is now completed, is shown 
in the frontispiece to this issue. On page 264 we give a 
back view of the building, showing two of the wings, 
taken from the site of the boiler-house excavations. 

It is expected that the entire building will be finished 
in about fifteen months from the date of the beginning 
of same. 

On page 263 we give a reproduction of a plan of one 
of the flooVs, showing the general arrangement of the 
beams and pillars. We may state that the particular 
method of reinforcement for the beams is that known 
under the name of " Coignet system of reinforcement of 
equal resistance." On this page we show a diagram, and 
it will be noticed that this method presents the advantages 
of the most economical sections of steel and concrete m 
any section of the beam, the section of the steel in ten- 
sion being greater in the middle portion of the beam and 
gradually growing less towards the points of support, m 
proportion to the bending moments. The ends of the 
bars are made use of to resist the shearing stresses by 
being bent upwards and hooked over a top bar. Ihe 
shear members are also spaced gradually closer together 
at each point of support. As shown in the sketch they 
are all bent at an angle of 45°. 

The reinforcement of the pillars consists of a certani 

number of longitudinal principal bars, bound by a spiral 

bar of small diameter. , r ■ • 1 

The slabs are composed of a meshwork of principal 

bars and distributing rods. , ■ ,u^ <> K^rro 

The cement being used in this work .s the Ferro- 

crete " brand, manufactured by the Associated Portland 

Cement Manufacturers (1900) Ltd. 

It may be interesting to mention that this is the 

third Post Office building which has been erected on th 

Coignet system of reinforced concrete for the Office of 

Works. 



262 



L ENOlNbLKINO ~-J 



=T=iTh 



POST OFFICE liUILDINCS. 



u 



fpfef-FT-fT^ 






^^M^n 




263 



REINFORCED CONCRETE. [CDNQ3ETE3 

The new General Post Office at Kino:ston, Jamaica, lor the Crown A-ents 
for the Colonies, has also recently l)ccn completed in this system, and m this 




particular ease the building has been designed with a special view to resist 

earthquake shocks. 

264 



r j-inNyrpticriaNAi,) 



RAfLWA y COXSTRUCTION. 








f^ m^^^r^-;^^ 






REINFORCED CONCRETE IN 
RAILWAY CONSTRUCTION. 



As much grejter use of rttnfoKed concrete for ratttvjy Vfork has keen made in America than in 
this country^ the principal examples in this article are taken from the United States^ and tve are 
indebted to the Atlas Cement Co, 'of Ne^w 'York for atlovjing us to reproduce some of the 
illustrations -which appeared in their recent booklet published on this sublect,—ED, 



1 111-; use of concntc in railway work is oiiu of extrciiiu im[X)rtancc, and the 
yrcat developments that have taken place in the last few years arc not sur- 
prisintj in view of the undoubted suitability of such a material for work where 
the question of maintenance is of primary consideration. It is undoubtedly 
economical for work executed on a lar.t;;c scale, as the bulk of the material 
required can usually be obtained within easy reach of the site, while the 
threatened shortatje in the timber supply renders it imperative for all ent,>-in€crs 
enijatjed in railroad construction to look for a suitable substitute, and it is 
questi()nal)le if any material can be found to equal that of concrete. 

'Ihe greatest advance has undoubtedly been made by American engineers, 
and till- reason for this is not dillicult to find. The European railways have 
imariably been constructed, in the first instance, in a more or less permanent 
manner, while the .\merican method has been to use a large amount of 
limber in bridges, stations, and freight sheds, owing to the great difTiculties 
h) he iivercomc and the corresponding large initial outlay, which prevented the 
use of more permanent materials until the increased importance and incomes 
of the railways, together with several disastrous fires, demanded the substitu- 
tion of more substantial structures. This entailed a gradual reconstruction 
of the railroads, which began with the adoption of wrought iron in the place 
of timber, and this was followed bv the extensive use of steel ; but eventually 
the adoption of concrete was brought about, and the American engineers have 
been quick to realise its many advantages. 

There is practicallv no possible use to which concrete cannot be adapted 
as a building material, and its suitability as a factor in railway work is 
demonstrated b\- the manv examples described in this article. Its cost is 
invariably higher than that of timber in the first instance, but it compares 
favourably with steel in this respc^'t, and the initial cost must not be considered 
alone, as the maintenance costs of a concrete structure are practically 
negligible, and it has been estimated that the elimination of painting expenses 
alone justifies an initial outlay of from lo to 15 per cent, over the first cost 

265 



RAILWAY CONSTRUCTION. 



KjONCKETEJ 



of a steei structure. W'ht-n compared with masonr\- or brickwork the cost 
of concrete is invariably much lower. The durability of concrete is also a 
great advantage, the strength increasing with age, and its freedom from 
vibration, owing to its solidity and lack of joints, is also greatly in its favour. 
When coal is stored in large quantities the danger from fire is very great, 
and the use of reinforced concrete for bins has been extensively adopted on 
account of the fire-resisting qualities which it possesses. These qualities render 
it especially suitable for stations, warehouses and similar buildings. By using 
sufficient reinforcement, properly disposed to prevent cracks occurring due to 
shrinkage from temperature, and by carefully mixing and placing the ingre- 
dients, concrete can be satisfactorily used without anv surface waterproofing, 
and this renders it very suitable for reservoirs, tanks, dams, conduits and 




N.J. Solid Sf 



similar structures, which must be essentially watertight. As a material lor 
retaining walls reinforced concrete enables a saving of much space and material, 
while providing a form of construction which is sound and reliable. 

It is a recognised fact that reinforced concrete needs very careful design 
and, what is equally as important, very careful execution to ensure success; 
and, however careful the calculations may have been made and the scheme 
considered, unless strict supervision is employed to secure good workmanship 
and the accurate placing of the reinforcement, the work will not be absolutely 
reliable. The cement must be good and uniform in quality, and the tests 
made sufficiently severe to guarantee good concrete, if the other ingredients 

266 



^ 



I. CON.VrUlKTlONA 
• EN(.INt.E.HlN( 



S 



RAILWA Y CONSTRUCTION. 



arc satisfactory in qiiality and proportion. The standard specifications should 
be adopted, as brief specifications are usually incomplete. 

The proportions to be adopted cannot, of course, be specified without first 
considering the nature of the structure itself; but wherever possible the pro- 
porlions that were actually used for the different evamplcs described in the 
latter part of this article are givi n. 

BRIDGES. 

The constructii)n of bridyes is, of course, one of the most important 
features in railroad work, and the use of reinforced concrete has given hii^hly 
satisfactory results in this class of construction where designed with int'^elli- 
gcnn. 'Jhe easy application to all types renders it invaluable under conditions 
which vxould make the use of steel or masonry very difficult, and the minimum 




amount ot material can be employed, with a consequent saving in outlay. The 
cost of a reinforced concrete bridge is nearly always considerably less than 
one constructed of masonry or timber, and, when the cost of piers and abut- 
ments is considered, a steel bridge can scarcely be said to have any substantial 
advantage in the matter of expense. In addition, the life of a wooden bridge 
|S about lo years, and that of a steel bridge about 40 years, and then careful 
inspection and maintenance are necessary; while a concrete bridge will last 
almost indefinitely, with practically no maintenance. The track is easily main- 
tamed on the latter structure, as ordinary ties and ballast can be used, instead 
of the more expensive bridge ties of a steel bridge. 

267 



RAILWAY CONSTRUCTION. 



ICONCBETE j 



Arch bridges can bf dixidcd roughly hito two types — those with soHd filled 
spandrils and those with the skeleton spnndril construction. The former type 

is usually employed for arches 



ol spans under looft., and 
where a tilling of \i'ry poor 
concrrU- is employed as a 
lining Ijetween the spandril 
walls it Ijecomes leallv a part 
ol the structure. In many 
cases, ho\ve\"er, the filling is 
executed with earth, sand, or 
cinders, deposited in thin 
lasers and well ranuiied in 
position. 

The Ijridge illustrated in 
Fig. I is a good example of 
the solid-filled spandril tvpe of 
construction. 1 his bridge 

consists of a reinforced con- 
crete arch of 54 ft. 3 in. clear 
.'^paii, with axis on a skew of 
22° 2' with the axis of the 
street. The abutments and 
wing walls rest on lo-in. piles, 
the last three rows in each 
abutment being driven with a 
batter to correspond with the 
inclination of the line of pres- 
sure. These piles were cut off 
below water level, which is 
about ID'S- ft. below the sur- 
face of the street, and a bed 
of broken stone, 3 ft. thick, 
was rammed around them to 
w ithin () in. ot the tops, where 
the concrete work started. 
For the arch ring the con- 
crete was mixed in the propor- 
tions of one part Portland 
•cement, two parts sand, and 
four parts i-in. screened 
broken stone; while for the 
abutments and wing walls the 
proportion was 1:3: *i, with lA in. stone; and for the spandril \\alls 1:3:5, 
with T-in. stone; with the exception of an open expansion joint, like a vertical 
268 




E 



.ONJTPmriONAl 



t-NdlNt-l l)IN(i 



^ 



RAILWA Y CONSTRUCriON. 



yrooxc an,l t„n-uc, iKtxv.in the ends of the abutnu nt^ :nul the ends of the wing 
walls, the bridge was constructed as a monolith. The main reinforccm.nt for 
the arch consists of .i-,n. curved round rods in lx,th intrados and extrados 
|)laced about 4 m. from the upper and lower surfaces. In the intrados they 
are spaced 12 in. -noart at the springing 11,^. and extend 5 ft. past the centre 
thus givmg a spacmg of ., in. for 32 ft. at the crown. In the extrados they 
are 12 m. apart at the abutments and carried 2 ft. (, in. bevond the centre line 
thus giving a 5-ft. lap for bond. ' 

.At the haunches auxiliary rods, about 2(, ft. long, are plac(<l in all the 
spaces between the main rods. .Alx>ve and below both the intrados and 
exirados rods horizontal transverse «-in. rods are spaced 24 in. apart and 
extend the lull length of the arch. The live load was assumed at 700 lb per 




sq ft. of surface, while the dead load was taken as follows : rails, ties and 
ballast, ,^o lb. per sq. ft. of surface; filling, ,00 lb. per cub. ft., and concrete 
lOo lb. per cub. ft. 

Including temperature stresses the maximum stress in the concrete was 
600 lb. per sq. in. compression, and 50 lb. per sq. in. shear; while the maximum 
■stress in the steel was 18,000 lb. per sq. in. in tension, and 5,000 lb. per sq in 
.n compression, the latter value being fixed, of course, by the permissible stress 
HI the concrete, times the ratio of elasticity of steel to concrete. The concrete 
m the abutments and the filling behind them was carried to a point atx)ut -> ft 
above the spring line of the arch, when the arch was put in at one operation 
concreting commencing simultaneously at the springing lines of both abut- 
ments. The whole of the concrete was mixed by machinery, and the traffic 
was maintained uninterruptedly on temporary trestles on either sid- of the 
bridsre. 



269 



RAILWAY CONSTRUCTION. 



ICQNCBETEJ 



An example of the skeleton spandril bridge is that illustrated in Fig. 2, 
which shows the Vermilion River Bridge, and this consists of three arches, 
the central span being 100 ft. and the two side spans 80 ft., with rises of 40 
and 30 ft. respectively. The arch rings are 3 ft. 6 in thick at the crown, 
deepening out towards the springing lines, and are reinforced near the e.Ktrados 
and intrados with i-in. corrugated bars, 12 in. apart and overlapped 4 ft. at 
their ends. Below these rods at the extrados and above them at the intrados 
there is a series of |-in. transverse bars, 33 ft. long, .\bove the arch rings of 
the main arches the channel piers are hollow, the pilasters being carried up as 
reinforced facing slabs, 15 ft. wide and 3 ft. bin. thick. The transverse walls 
are formed by the piers of the spiiiidril arches !iext to the springings, which 




have bracl-:ets at the top projecting 12 in. on the inside. These brackets carry 
reinforced concrete slabs 2 ft. thick, which, being freely supported on rails 
embedded in the tops of the piers, and bearing against similar rails projecting 
from the underside of the slabs, act as expansion joints. A similar transverse 
expansion joint is placed over the top of each abutment. The concrete in these 
joints was made as smooth and flat as possible, and finished so that contact 
between the adjacent faces at the point is made only through the embedded 
rails. To further separate the division two layers of felt are placed between 
the two surfaces of concrete and carried up to within 2 in. of the top of the 
vertical joints, the remaining space being filled with asphalte. The concrete 

270 



[A-aoSL^p'.NTil-l RAILWAY CONSTRUCTION. 

lor tlic niiiloncd p<iilk)ii.s was mixed in Ilic proportions of one part ccnu-iU 
to two parts cli-an sand to four parts broken stone ; that for the abutments 
and main piers of 1:3: 6, and the footings of 1:4:8 proportions. 

TRESTLES. 
'I'he use of reinfoned concrete for trestles is becoming very extensive, 
and it has proved very satisfactory for this chiss of work. Very careful 
design is, however, necessary on account of its hght nature, and many con- 
servative engineers do not care to adopt this method of bridge construction. 
Many \ery large schemes have, however, Ijeen successfully carried out in 
recent years, and one of the most interesting of these is the Richmond and 
Chesapeake Hay X'iaduct, illustrated in /•"/>.<. 3 and 4. This viaduct is 2,800 ft. 



1* 




long, while the height varies from 18 ft. at either end to 70 ft. at its highest 
point. 

It was designed to carry a 7S-ton car, and it was assumed that the viaduct 
should carry its dead load and the entire live load, plus 50 per cent, of the 
live load for impact. .An aJlovvance was also made for the thrust, due to the 
braking of trains, of 20 per cent, of the live load; and wind pressure was 
figured at 30 lb. per sq. ft. on the surface of train and viaduct. The concrete 
for the superstructure was mixed in the proportion of one part Portland cement, 
two parts granite dust, and four parts f-in. crushed granit.- ; and in the footings 
a mixture of i : 2i : 5 w^as employed. The reinforcement throughout was com- 
posed of Kahn trussed bars, and in proportioning the footings a bearing 
value of 3 tons per sq. ft. was allowed. The viaduct itself is comprised of 
a system of girders of rectangular cross section, varying in span from 23 to 
68 ft., supported by a series of interlaced and battered bents, varving from 



RAILWAY COXSTRi'CTION. [CONCRETE] 

14 to 70 ft. in height. Expansion joints were provided where the short 
girders rest on the column brackets at intervals of about 200 ft., consisting 
of a grooved steel plate on the top of the bent, on which a grooved steel 
plate on the bottom of the girder slides. Steel connections are also provided 
to prevent any tendency of overturning the girder. After the erection of the 
forms the columns and struts up to the bottom of the girders were poured at 
one continuous operation. The girders and floors were constructed in a 
similar manner. The girder sides were removed at the end of a week, while 




Fig. 7. CuLVEKi ox the N.E Railway at Kilio.-j. 

the remaining forms and supporting falsework were left in place for at least 
thirty days, .'^fter the removal of the forms the entire surface of the viaduct 
was given a finish of sand and cement, applied with a brush. 

CONCRETE PILE TRESTLES. 

These trestles, which replace similar wooden structures, possess a number 
of features comparatively new to the field of concrete construction. The illustra- 
tion {Fig. 5) gives a general idea of this type of construction, which consists 
of six pile bents spaced 14, 15 or 16 ft., centres with an average height of 
10 ft. Two types of piles are used — namely, rectangular cast piles and Cheno- 
weth rolled piles. The former are 16 in. square at the top, with 4-in. chamfers: 
and the reinforcement consists of tight i-in. bars wired to a spiral coi' of wire 
of varying pitch. They are made in lengths up to 30 ft. The Chenoweth 
rolled pile is circular in section, 16 in. in diameter, and is reinforced with 
i-in. corrugated bars, wound spirally with i-in. mesh wire netting. The piles 
are driven by an ordinary pile-driver with a 3,000 lb. hammer falling 24 ft., 
and are finished at the head bv deep reinforced concrete cross girders, which 

272 



I&tg^tSKV'jN?:^-!!] RAIIAVAV CONSTRUCTION. 

supiKMl ihr slabs lorming the floor or deck. The concrete for the piles is 
mixed In ihc proportion of one part cement to three parts fine screened ijravel, 
while liir ihe caps and g-irder slabs a mixture of one part cement, two sand 
<m(l lour ol stone is used. 

CULVERTS. 
All classes of culverts have been constructi-d in concrete, from the small 
pipe to the large reinforced arch and box types. On account of its greater 
simi)lieity, and the less expensive abutments required, the reinforced flat-top 
<iilveii, with abutments of reinforced concrete, is more economical for short 
spans tlian ihe arch type. .\ good example of the box culvert is that illus- 




trated in Fig. 6, which shows the Indian Creek Culvert on the Kansas City, 
Mexico and Orient Railway. This is 250 ft. long and 14 ft. bv 15 ft. inside 
sizes, while an interesting feature in the design is the use of reinforced struts 
spaced at 8-ft. centres, instead of a solid concrete invert. The reinforcement 
consisted of | in. corrugated bars, and the concrete was composed of one part 
•cement, three parts river sand, and five parts crashed limestone. 

\\'e also reproduce, in Fig. 7, a photograph of the reinforced concrete 
■culvert on the X.E. Railway at Kilton, which appeared in our March issue, as 
being an excellent sample of a railway culvert. The work on this culvert was 
•designed and carried out bv the Trussed Concrete Steel Co., of "Westminster 
S.W. 

PIERS AND ABUTMENTS. 

Concrete may be used for bridge piers either plain or reinforced. If re- 
jntorccd concrete be emplincd there may be quite a saving by reducing the size 



RAILWAY CONSTRUCTION. 



[QQNCKETEJ 



of th. pier or h. makin, it hollow with reinforced walls, ,n which case the 
open space is ei'ther filled with sand, broken stone or gravel. When it ,s 
desic^ned with sufl.eient stability it is left open, thus making a considerable 
redvrction in the load on the foundation. A good example of these p.ers.s 
hat shown in Fi,. 8, which is a photograph of some work executed on the 
Paterson and SutTern Kailwav. Much use has also been n.ade of reinforced 
concrete in the construction of abutments for bridges, and the savmg .n 




n^atcrials has been in some instances so great as to reduce the cost as much 

^* +° P^' "'"'■ RETAINING WALLS. 

The use of both plain and reinforced concrete for retaining wall construc- 
; u . fV,rv o-<.neral and is not confined to railway work alone. 

T ^^dwXaret^uflnie economical than those built of plain concrete, 
Sril 1 t tT; r^ot aHow the material to be fully utilised, because 
the sect on must be made heavy enough to prevent overturning by its own 
tight" wITh reinforced walls the counterfort type, which is illustrate in 
Fi. o is generally economical where the height exceeds about i8 ft It is 
neSssm-y in all retaining walls of any considerable length to provide for con- 
:raction Iv placing ioints at intervals, and by the provision of --gh hon.ont^ 
reinforcement the temperature stresses can be so distributed that the cracks 
will be verv minute and scarcely noticeable. Careful attention should also be 
eiven to the earth filling and its drainage. 

The next article will deal with stations and other types of railuay 

construction. 



E 



77//-; LE CI! ATELIER BOILING TEST. 




RECENT VIEWS ON 
CONCRETE AND REIN- 
FORCED CONCRETE. 

THE CCNCPETE INSTITUTE. 



SV,<-.>/,>.: „„ „,.(,.. / , , ,■ '■' . - ■■ -J Discussions prcsenlej ttfore Trchmcjl 

neJj'p7't,!'°e-''"ED.'' '"''""'"*' °f <I'-"IJ>"9 Iht suHects Into sections. Is. -wc bellrvt, a 



A c.KNiiKAi. „uciin- ,)l the Concrete Institute was held at tlie Roval Lfnited 
Service l„Mltnlin„, Whitehall, S.W., on March 17th, at uhich there was a 
corisiderahle allriularKe of members and visitors. 

The paper on this occasion was hy Mr. I). B. lUitler, .\..M. Inst.C.E., 
I-.CS., and the discussion was a particularly inlercstins,'- one. We sjive a 
lengthy summary of both. 

NOTES ON THE LE CHATELIER BOILING TEST OF 
PORTLAND CEMENT. 

Paper by D. B. BU FLLR. .A.M.lnsi.C.t: , 1 C.S. 
Mr. Bertram Blomit, F.I.C., Member of Council „/ the Concrete Insl,y,le, presiied. 
.MR. D. B. BUTLER. Reader of the Paper. 
Ix the author's opinion, ihe soundness of Porlland cement, i.e.. its freedom from 
expiinsion (" mv.ariabiliie de volume " or " volumenheslandiokeit, " to give its French 
and German equivalents respectively), was its most essential pro[x;rtv, and should be 
always the first thmj,^ to be determined in estimating: the constructive value of a 
sample. It was obvious that, notwithstanding other 'hitjhlv desirable qualities which 
a cement miK'ht [xjssess, such as -reat strength or lar-e'sand-carrvins capacity, if 
It was unsound, and contained certain elements which subsequently caused expansion 
with, in extreme cases, disintegration and crumbling, it was not onlv of no use as 
.T constructive material, but was at once converted into a destructive material. 
.Although with the improved methods of manufacture obtaining of recent years these 
extreme cases of disintegration had become more and more rare, expansion of a more 
or less dangerous nature was not infrequently met with. 

Tests for Soundness.— The original test for soundness, the author explained, was 
based mure ,ir less c.n working conditions, i.e., pats or cakes of neat cement plunged 
into cold water when set, or after 24 hours in air, and examined at intervals; if 
at the end of a month they showed no signs of cracking or distortion, and adhered 
hrmly to the glass plate on which thev were made, the cement was considered satis- 
factory as regards soundness. This test laboured under the obvious disadvantage 
that 28 days had to elapse before a definite opinion could be pronounced, and the 
cement finally accepted for use, a delav that was frequentlv impossible in practice 
although It might be argued that the generallv specified iS da\s' tensile tests laboured 
under the same disadvantage. 

To obviate this long delay, several accelerated tests for soundness have been 
evolved from time to time. About thirty years ago the late Henry Faija introduced a 
test for soundness, consisting in subjecting cement pats to 7 hours in moist air of 

Z75 



THE CONCRETE INSTITUTE. 1 C0NCRE:IK J 

2 days in water of 176°/- . ^_ ,;, n " Void water- while after a further 4 days in hot 
:I:Lr^'/^Id::ytntS'^^s lnrt:^^the s.ren.th developed was supposed 
r^c:;:;parah.^ with t da^. a. . .^J>V coLd^wa er ^ ^^ ^^^ 

THe Bomm ^-';7 VnTh *il^' eVai-d o tle'di^^^^^ of always i.aintah.ing an 
boiling test "°^\'" r°f>"^:'^op X boiling test is certainly considerably simpler; the 
equable temperature oi i ,0 f-, tne .0°""^ ^Inwin.- a pat to set 24 hours in a damp 
ordinary qualitative boiling test consisted «f ^' "^^'^V ,^\P^ %:,A^.-A-< raised to boiling 
box of 60° F., and then placing it '" ';Old^^ '''*";• after whicli treatment the pat should 
and maintained -^ ^J^^^^^^:^^ ^:; sometinu-s further specified that the 
S::s^ uirS^rll^ul^'a^^br::^';; with a sharp crisp ring, which was a very sure 
indication that it was free '-'" -;;,'^';%°;Sf,f ^X and depended more or less on 

of prisms or square bars .00 mm ""f -f^, ;„"•,, ^> ,^;„th of the bar to within 
delicacv of the instrument was such ^^f =^[^^''";i?j, ",,",^,,t,r^ It, however, required 

mining expansion was that devised by M. Le ^^^''•' ^^ ' j^^j of determining the 
revised British standard Specification of 1,0 ucre a W^^^^^^ ^^^ ^^^^^ ._^ 

ease';^ T g^t^S.^llnsl^n TIi^:? .0 ^tliUnSres after .4 hours' aeration and 

cvlinder of spring brass or other suitable me a o ° ^^^^J '^fj,;;;;, ^^^ ,„;„;. 
thickness, forming a mould 3" l"' '-^^.^f.^r^ttied tw^^^ with'pointed 

:::ir tl^^^aS t^£:l^^ ;:!";he^n::rof the cyimder being 165 milli- 

-^'^^Hc:::i:;cting the test, the mould^is ^^e Pj-tlT uUe;:^;:!^ t^ S^^ 
and filled with cen-ient gauged '" ^^ "f "''' ^/^^ ;„'„" ,! b" ng perfornted. The mould 
of the mould gently together while th'^ °per«Uon ,^ b ^y .^ ^^ ^^ ^,^ 

is then to be covered vyith another Sl>-'ss plate a ^ ,,.,,ter at a temperature of 5S 
this and the mould is then to be immediateh placed in H 

to 6'4 degrees Fahrenheit, and left there for 34 hour- ^^ ^^ ^^^^^^^^^^ ^^^ ^,^ 

" The distance separating the inc.cator point boiling-point in 15 to 

bs;rr.f=tprs.vrri^:.'r;'';s"'„:'sr:,o, e.„. ,.e , 

down in this specification." Bauschinger apparatus, that it was cheap 

It certainly had this advantage over the '^^"^™'"- y\^.^^ e ,allv accurate was 

and simple, and involved no costly '-^^d n-lrv nrofessiona esting work, the author 

open to discussion. In the course "^ ""^^ "^^^^.^of ests for soundness by the I.e 

k^i^L^'Z thrLnfiL^reSrhetad sometimes obtained had led him 



THE LE CH ATELIER BOILING TEST. 



(ci ihe conclusion Ih.il w hcii' tlu- conilrinnalion of a cnncnt f(jr iinsoundni-ss was 
concerned, the rc>ull> <^iven by the Le C'halclicr test ;,lioiikl not be too rigidiv inter- 
preted. 

riie author then quoted a series of experiuKMits to sliow Ihe variable results which 
niif^ht be obtained by dilTerent operators, and even by the same operator working; under 
exactly the same conditions. 

In order to jiscertain if dilTerences in the elasticity of the moulds were in anv way 
responsible for the vari;ible results obtained, the author devised a special apparatus. 
The variation tjiven by dilTerent moulds was considerable. However, the results did 
not definitely point to differences in the elasticity of the mould as bein^ responsible for 
the variable results obtained, since No. lo, which was an extremely weak mould, j^ave 
the least expansion in two cases out of three. 

it was thoutjht possible that the position of the test pieces in the boilintj bath, 
whether in the centre or round the outside, mi).jht have had something to do with the 
variations found, and tests were therefore made to .ascertain if this were so, but the 
results suss'esled th.il this u.is not the case. Nor did variations in time of cooling 
after boilintj appear lo .affect Ihe result in .my w.ay. 

Differences Due to Aeration.- -.\no\\iLT curious feature about the I.e Chaielier test 
w.is Ih.il insl.inces wen- very frequently met with in which the expansion was con- 
siderably greater after days' .aeration of the sample th.an when first received, or after 
only 14 hours' aeration. l-'rom the |X)int of view of ,a test for soundness this was an 
obvious absurdity, since it was a well known .and ihoroufjhly acknowledfjed fact that 
cement improve^l with aeration as rej^ards soundness; it therefore very strongly 
suggested that the increased exp.ansion of such samples u\ion boiling was dxie to causes 
altogether outside the question of soundness as it was generally understood, i.e., the 
presence of disruptive .agencies within the cement itself, which would eventually cause 
expan>ion under ordin.irv working eondilions. 

Less Expansion on Boiling than In Cold Water. — In a paper re.id before the 
<'nncrcte Institute in May last on the setting projx'rlies, etc., of Portland cement, 
Mr. H. K. G. U.'imber referrtxl at considerable length to the I.e Chatclier boiling test 
and raised one or two very interesting points. lie first of all drew attention to the 
f.ul that the expansion of the specimen during the preliminary 24 Jiours' immersion in 
cold water was altogether ignored, only the subsequent expansion during boiling being 
taken into account, and pointed out that instances frequently occurred in which the 
expansion in cold w.-iter w;is considerable, whereas that resulting on boiling was 
negligible. The .author of the present paper s.aid he could fully bear out that state- 
ment, for it was the custom in his testing-room to record in every case the expansion 
caused by previous immersion in cold water, as well as after boiling, and in many 
cases, more especially with slow-setting cement, the ex'pansion in cold w.ater was very 
much more serious than that due to boiling. 

.Surely it was more important to record the exp.ansion under actu.il working cnn- 
tlilions in cold water than that produced bv boiling, for wh.atever the value of boiling 
as ,111 accelerated test for soundness, cement was rarely, if ever, subjected to boiling 
w.iler in practice. 

Slowly Hardening Cements. — Mr. Baniber also referred to the somewhat 
;\rbiir,iry condition of only allowing the cement 24 hours to harden under water, before 
being subjected to the boiling water, and suggested that failure was frequently due 
to the cement, more especiallv the slowly hardening varieties, not having had time 
to sufficiently harden in that brief jieriod to withstand boiling water; he gave an 
instance in which cement tested imder British .Standard Specification conditions gave 
15 mm. expansion, but when allowed 3 to 7 days' preliminary hardening under water, the 
expansion was reduced to to mm. and i"5 mm. respectively, while, if allowed 24 hours' 
hardening in air, instead of water, there was no expansion wh.-itever. 

Expansion of Coarse Particles. — Referring once more to Mr. Bamber's paper, 
the author gave as one reason of cement sometimes failing to pass the Le Chatelier 
test, the inability of the coarse particles, or unpulverised clinker, to withstand boiling 
water w-ithout expansion, and expressed the opinion that " it has yet to be proved " 
that because such unijulverised material caused exfiansion when submitted to boiling 
■water, that it would also cause expansion under ordinary working conditions in cold 

E 277 



THE CONCRETE INSTITUTE. 



,v.ter X\-ith this the author quite agreed, and quoted experin.ent. which showed 

the author sujjsested, to justit} nib ■^'^m-"" ' „„,„„rned the results triven bv the 
condemnation of a cement for unsoundness was conarnec the ^^ S ^^^ ._^^^^ 

Le Chatelier boiling test should not be too ng.dl> '"'^^P^ted^ P^ ^^^ tion 

of anomalies and conflicting results ^°"7"fy";^^,;^'t4seit^ would not withstand 
whether a cement should be =°"tTn'rthetir°h"f 24 ho"^V preliminary hardening 
boiling water 24 hours after &^"g'"f';^'™ if ';Vs .a significant fact 'that in the 
was in cold water or m air. On t'^'VP™"' ' ' i^"; ... i^^^n ;„ operation for many 
German f-<^-iJ^"'-.l e'r^'nt"? r::^l^N.u£sNvl"c; 'hT author understood only 

s'^;^;JJt- ^nct^^ before ^f^^^^^j^ij^ ^':i:::^^z 

altogether ignored, reliance being placed on the ,S Ja ~ld ^ accelerated tests 

thecommencement of thispap . ^'^f ^^^Zh^,,u,s some few years ago, 
was very thoroughly investigaieci d\ luc >. pprmnn technolosjists have always 

and haying regard to the leading 1--"°" ^^^^ . ^f*^ ^.^f \;Tt su h^tests were found 
held in matters ^ff^^^^^^'^^ condemn good aZ bad cement alike, 
to be unrehable. i.e., '^^ "; 'm^ fo be considerable difference of opinion as regards 
In America, too, there seemed to be consiaerame Engineers' Specification 

the yalue of boiling tests. "^he .Wr.can Soc,et> o O .^ g^ ^^^^P« .. _^ 

included the following accelerated test, as we U «s "orn ^^^^^^^ .^ 

ex,x,sed in any conyenient way in f/\ ^^'^^ ^^^"^^ hard^^ing being infold moist 
a loosely closed vessel for 3 ho"--^. ''-LPuniriowet^r rather significant, i.e.:- 

tests." , mip-ht lie for or against accelerated tests, the 

Whatever excellent reasons there miRht M 10 ^ considerably less than 

author could vouch from P'^'Z''\TSTZtuZ\ cement manufactured in England or 
twenty years ago not 10 Pf ,«".*• °(^.*^^;°''jerhe foregoing conditions; the obvious 
elsewhere would -'thstai^d boi ing w a. r -"f;j^'^lXr%undness, 90 per cent, of the 
inference, therefore, was that if ^ue ^ v^^s a hundreds of thousands 

cement used twenty years ago was unsound- niis >'^^; ^^.„,.,,j ,,.,, „ther a 

of tons then used for "-P-lj;"\.r;TArd tcf the e^^^^^^^^^^^^ "f --''^ --'^ "' "^^ 

;^^Si!:™!^:^s:^; thi'r;d^c:^^ ^ seriously maintained. 

, .. . yery p.a.nt -ty an^^^^^llf^^^^^ 
their disposal to Mr. Butler for his p per ^^^ ^^l^^,,^,, , He would also like to be-aUowed 
labour that it involved, and for it, P^''^'^' l""""' j,/ u^tler appeared to suppose that, because 

,0 make a brief cotnn^en. on tl--^"™ ;;„"t ^hTt, had fliled.-to prepare cement of the admirable 
certain nations, the German and A"^«"^f"' 'i^' ,hm,ld go back and put" the clock some 20 years 
^I Zt^r^:^<S^ S^:^ ::tb^'^.er there, a^d that was the summary of 
hi; "hicit He would now ask Mr. Bamber to open the d.cussion. 

"h^-"v'^obec^aitdup™\o^"°ntt"dtus;ion'^^^^ this most interesting 
He took it as a great honour to ^<=.7"™ Y^,"^;^^/, „ ,he author for the very estimable.way m 
paper. He would first of all add h^ ™^■^fBut'e had rendered a conspicuous service, not only to 
..hich he had dealt with th. sub ec. Mr. But 1- ^ ^^ ^^^^^^^ ^^^ ^^^^^.^^^ ^^^^ ^^ ^^^ 

the engineering profession, l-"/ also to tn jj,^^, difficulties which were so promment 

in his paper, the d.-"-ion o wh^ch t nded^ to elu ^^^ ^ ^^^ ^^^ ^^^^^^ n^anufacti^er 

at the present time in <:o°"^f °"- '^/^ * , '""th the subject from a somewhat comparative pomt of 
T,eFa,i.Test.-Ur Butler ^^d dealt - h th ubject ^^^ ^^^^^^^^^^ ^^ ^^^^^^_ ^^ 

view, insomuch as he had described he ^anons met^o ^J ^^^^^^ ^^^^^^^^ ^^^^ 

puts first and foremost the Farja test f J^'j^ f^'^j^ ',;, i„i„„, ,,hich was very much that of 
done by reason of its ^'"Vort^^'^or oi ^s^mu^T^ J ^^^^^ ^ ^^^ j,^^„„^, 3„^ewhat 

rt'^o^trbr're^^er::!::!^:" S^ra:rof he tact that the manufacturer knew that if 
a'y ceme-nt he made failed .0 pass the Fa.Ja test it must be bad indeed. 
278 



m 



. llDNyiBIKTlONAl 



.N(.iNt.ti;iN>. -J Jtlh Lh CIIA n-.IJHR liOllJSc; TEST. 



Devat Test.-Mv. Bu Icr then described the Deval test, which was certainly a much more severe 
est than the one wh.cli he (Mr. Butler) continuously reco.nmended. Speaking as a manufacturer, 
he had looked upon the Deval test as one of the most important which the manufacturer had at 
Ins command. His experience, which was somewhat large in this matter, had led liim to the con- 
clusion that, if any cement for which he was responsible was capable of passing this Deval test— 
which was a test which extended over a period of seven days-there was not the slightest necessity 
or any menta disturbance <.f the kind Mr. Butler had referred to. For his part he considered the 
I oval test as the n.ost satisfactory one, from the expert's and also from the manufacturer's point 
of view, that could possibly be invented. ' 

Mr. Butler then got on to the more severe test of boiling, and described later Dr. lirdraenger's 
and D._ Heintze s me hods bu, he had cmntted a test, which was known technicallv in the trade 
as the boiled balls test. This consisted of mixing up a certain quantity of cement, and placing it 
in a piece of linen, and immersing it in a receptacle which contained water, and boiUng it for a certain 



period, 



UChaMUr Tm/.-Hc was glad to see that Mr. Butler described the Le Chatelier test as a cheap 
and simple one and he ,|u.te agreed with the remark of Mr. Butler that the results of this test should 
not be too rigidly interpreted. His experience of this test had been that when quest ^s had arlen 
between the manufacturer and the expert in connection with the slight variations or excesses over 
specification requirements, where the manufacturer had had an opportunitv of discussing the matter 
with the engineer, toge her with the expert, in almost all cases the engineer was willing fnd anxious 

a:::;;:^.^:r'^s::' '"^ '^^'^ " '-' -^- --^ "'^•'-' "- -^ "—*- '- ---ion with 

Under the heading, '■Variations in Time of Cooling .After Boiling," Mr. Butler said- "It is 
frequently desirable, in order to save three days' delay, that moulds should be filled on Friday 
and consequently boiled on Saturday. Since the requisite six hours' boiling is not coraoleted ,mti 
after the usual Saturday working hours, the only way in such cases is to instnicrsor'^es;ons ^e 
person residen upon the premises to turn out the gas under the boiler at a certain hourlnd 
eave the moulds m cold water till .Monday morning before measurement." Now, the first thin > 
that struck him in connection with that was that the expert perhaps should devise some better method 

I'^rre'-oT'lL^S "" ''' '-' "'^" '' ''-'"' " "^ -- -"»-'>-<= P-- - -'™ "- i" 
Expansion In Cold Wster.~Mv. Butler also referred to certain remarks which he (.Mr. Bamber) 
had made m a pa,..r which he read recently to this Institute, and he was glad to see Mr B itle 
agreed with lum that some alteration should be made in the Le Chatelier te'ft to deal with the et 
pansion which sometimes took place in cold water before the cement was boiled. In nine case, oiit 
of ten where that preliminary expansion in cold water took place it was due more or less to the pres- 
ence of gypsum in certain proportions. .As a result of communication with U. Le Chatelier who 
had not noticed this peculiarity in connection with his test, he himself suggested it would be a' good 

1 ing o modify the test m some form so that this expansion in cold water might be recor<led M I e 
nt't c',r "'' "", '""v '1 '" '''' ''^ "'""'^ investigate this particular point, and that he thought' the 
particular apparatus which was now in use was not perhaps sufficiently delicate to determine thi! 
preliminary expansion, and he suggested, or offered to make some suggestion, a, to some modified 

orm of appai-atus whereby this preliminary expansion might be determined. He had not yerhefrd 

rom MLe Chatelier with reference to this point, but Mr. Bamber thought it was one whi h shou d 
be dealt with, because he was firmly of opinion that a cement which expanded considerab y in cod 
when'boned""'' '"''™"' "" ""' ''"'"' '''' ""''"'^' '"""'' '" ^"^ ^-="«^. and explinded only 
Mr. Butler again referred to the probabiUty of the expansion in the Le Chatelier test being fre- 
quently caused by he greater particles of unground clinker present in the cement. He was Id 
to see that Mr. Butler's tests and his experiments practically confirmed that opinion, but he would 

T , -.T'' '""'^"'^ ■' ^''- ^""^^^ ™"''' ''^'^ '"'<' 'hem whv these particles of cement expLded 
mlttXT "" '"" ""■'"'" "' "■"'™'' "■'■"" '-'"' ""''"'' °' '"« same chemic;. cha'acfer 

.hpY^'rw*?^" '" ""^ '"'"'°''' '^™^'"^i™^. it "-as generally accepted bv the cement trade that 
the Le Chateher test was one which could be complied with : and, in his opinion, the engineer what 
ever his views might be as to the comparative value of the test recommended by .MBuL-the 

W ce^' ,': ''"T. '"' "-l '^"^'^"''^ '^^'-'""^' '' '<'^^' "-^ '° '"« — ln-°n that in pi^chasin' 
hs cement It was better to have that which would pass the more severe test, even if it was foo severe" 
Uian one which would not do so. He would again reiterate that he thought, in respec trtheLprove: 
Than rnvthin " thev h H ""Yf" ^^ ^' \''" °' '""^^ ^'^'"^ '° "'<^ — ' '-'^'^ - thts "o.^ rv 
epute had out h m elf ■"■'' '^^t'' . "' ?'"• ""^ '"^''^^"^ "'-'''' ^^'"^'>' manufacturer of anv 
repute had put himself in a position to comply with it. He would be sorry to see a return to the 
less severe tests invented by Faija some twenty years ago. 
E 2 

279 



THE CONCRETE INSTITUTE. \QP^Cli¥2Xl 

MR. W. J. COOPER, F.C.S. 

Since it. inception he had taken the greatest interest in the Le Chatelier test and to a certain 
extent was in accord with it ; but on some points he was not, as it seemed to him to be based on a 
™ foundation. It was assumed that the combmations which took place m the case of a cement 
iTcontacrwith water at a temperature of 21- F., were the same as those which occurred at lower 
^mperatures say, up to 100° F. That point, so far as he was aware, had not been proved, 
temperatures, sa>,p ^^ ^^ ^^^ ^^^^^ ^^ ^^^ ^^^^ ^^^^ concerned, he was prepared to grant that 

in thf majority of cases, if a cement complied with it satisfactorily, it was sound and could be 
eUed upon in everv wav; but he did not think that this could be taken as an '-;f"^^'^./"":- ^^e L^ 
he knew nmuerous instances where a cement had given little or no expansion when boiled m the Le 
ChaTeta r^uld, but had ultimatelv failed by expansion, and in one case, at lea^t, had disintegrated 
on i^so^raccount. On the other hand, if a cement failed to comply with the test, he really could 
^ot a. Tat such failure was any evidence that that cement was unsound, l^^^^^-^^^ ^^^^^^'^ 
why this view should be taken, one of which was that cement, whether quick setting or ^1°^- =^"'"g' 
^a boiled after setting for an arbitrary period-,..., m .4 hours after ^-gmg Perhaps m th 
majority of cases this time might be sufficient, but m other cases it certamly was not. He had one 
"ase before him where a cement, when boiled for 24 hours, gave an expansion "«. 4° ■"'"• "^ 
knew the cement was som^d. It was one with which he had made extensive experiments, and he 
'heTfore made a large number of pats or blocks, and boiled them at varying P--/-''^ f^f^,^. 
As the period of time between gauging and boiling increased, so the expansion decreased. It started 
at" 10 mm at 24 hours, and it gradually shrunk down to 2 mm. at 2S days. At three 
mon hs'he expansion was absolutely nil, either in cold water or on boiling. That ceme t ™,,d 
have been condemned as a very bad sample, as a ^•ery unsound cement if ^"'l^'^^^'lj'jj^'^^ 
Chatelier test If it had been so, when boiled at three months its unsoundness should have de^ elopea 
Ld have be ome apparent. Instead of that there was no expansion in the sample when taken from 
^e COM water before boihng, and boiUng produced no further expansion. Not satished with bo.hng 
his three months' old sample for six hours, it was kept boiling for 24 hours, and the expansion was 
stnini! He therefore thought that if a cement failed when boiled 24 hours after gaugmg, .tshou.d not 
be judged guilty but should be allowed to produce some eNidence of its soundness by being given 
an extension of 'time, and a further sample boiled after setting for, say. three days. 

Aelatlcn-lt was generally admitted that a cement which was spread out and aerated was improved 
in soundner;. Now, In his experience-which covered a great variety of cements -eluding the 
burnt in rotatory kilns-he found not infrequently that a cement got worse on aeration. Smgularh 
en^gh he hid an example in his own manufacture only last week. .^ sample was taken direct from 
the inil spout and gauged, five minutes after grinding that sample gave an expansion of about S mm. 
It' ™ allowed to sfanl si^ hours, and a further sample gauged. It then gave an expansion of abou 
, mm I va then aerated for 24 hours, and a further sample gauged, when the expansion lumped 
ulTo somewhere about 30 mm., and that expansion increased for some time with aeration, but eventu- 
anyb;grTo recede. Now, that same sample of cement when allowed to set, after being gauged, for 
a L^r^eriod than 24 hours, gave normal results. He had yet to learn that any satisfactory explana- 
tion had been advanced as to why a cement should apparently become more unsound after aeration. 
Mr F T Tristram: You mean unsound on boiling ? .-j . 

Mr. Cooper: He meant unsound as judged by the test in question, which, in his opmion, dad not 
always indicate genuine unsoundness. j . .t,^ ^,.„an 

Lpsnsion of Cement in Cola Wa/er.-Mr. Bamber made some remarks with regard to the e.xpai - 
sion of cement in cold water. He was very much interested in the statements he put forward m his 
paper on the '■ Setting of Cement," and he (Mr. Cooper) had canied out some experiments which at 
first appeared to contradict them, and wrote to Mr. Bamber to that effect. Since then he had earned 
out many more experiments, and he found in some cases that the addition of gypsum to cement, which 
expanded considerably in cold water and also considerably on boihng, reduced 'he expansion m cold 
water-in some cases it became absolutely nil. It also reduced the expansion ..n boding in other cases 
and he thought these were in the majority. Further experiments showed that the expansion in co d 
Tater was sometimes increased bv the addition of gv-p^um. and he found that when the e-pansion n 
cold water was considerably increased, the expansion in hot water was sometimes almost complete 1> 
abolished. 

MR GORDON NICOL. M.Inst.C.E. (Engineer to the Aberdeen Harbour Board.) 
For the last 16 years he had carried out the boihng test of cement, and carried it out very rigidly, 
and perhaps rather more severely than others, because he had always specified, after gaugmg and 
remaking ^n a moist atmosphere for 24 hours, that it should be boiled for 48 hours, his impression 
beinr, from some of the tests carried out. that in a comparatively short period the cement migh 
escap^ detection, where in the longer period it would necessarily be detected. Of course, it mrgh 
be argued that it was too severe a test, and he could quite understand the manufacturer argumg that 
point" but at the present moment thev did get the cement manufacturer to standjhis test. Most 



r..coN.v.p.>c-noNAi.i -pHE LB CHATHLIRR BOIIJXG THST. 

[tX£N<ii:V«:.KlNt. — J 

of the ci-iiic'iit which he was using passed such a lest, and until cnie had discovi-red another which 
was more reliable he thDiight the engineer would like to be assured through this that his cement was 
sound. Personally he felt that it did to a considerable extent test the soundness of the cement. The 
Le Chatelier was one which he had used for some time so that he might comply with that portion 
of the British Standard Specification, but certainly it was on a longer period of boiling that he had 
always determined whether, in his opinion, the cement was suitable for the work. 

Causes of Unsouadness. — It had been said that the core really was somewhat responsible for the 
deterioration or disintet;ration which took place under this boiling test, and he remembered on many 
occasions, when visiting the cement factories, having taken the tailings from the wet grindings and 
discovering a considerable number of particles which had not been reduced in the process of wet 
grinding, and he had always held the opinion that that to a great extent had been the cause of the 
disruption that took place in the cement, those particles not being reduced, passing into the fuel and 
having considerable volume in themselves, being prevented from chemically uniting with the other 
ingredients in the cement, but having that little kernel of what became caustic lime in the centre, and 
this hot water reaching the little kernel and causing the disruption. 

There might, of course, be other causes, such as free lime or o\'crliming, which caused the un- 
soundness, and it might be said that this test was one which subjected the cement to conditions which 
it w^uld ue\'er meet in practice — that the cement, practically speaking, in the large mass of work 
was never subjected to boiling water, and never subject to an exci'ssive temperature of any kind. 
That was a point on which he felt at a loss altogether, as regards explaining what the cflfect of the 
boiling water was in penetrating the cement, in getting to these little particles which were considered 
as embedded in the mass and ultimately causing the rupture. 

Test tor Unsouadness. He had had many cases where cements had gi\en way and where large 
expansion had taken place, the expansion in the 48 hours reaching about 25 per cent, of the length of 
the testing place. But latterly he had felt that even a more severe test to apply to the cement for 
soundness was that of breaking the bricqucttei, after the boiling, and comparing them with the strength 
of the bricquettes before boiling, and he specified that the cement hydrated, kept in the moist atmosphere 
for 24 hours, and boiled for 48 hours was to be compared with a bricquette in the moist air for 24 hours and 
put under water for 48 hours, to make it the same age as the boiled bricquette, when it was taken from 
the boiling water ; that that bricquette should show an increase of tensile strength of 30 per cent. 
It might appear to be a very severe requirement in the cement, but he got it, and the manufacturer 
did not object to give it, and he discovered in that test the acceleration of the strength while showing 
no disruption of the material ; and recently in one of the cargoes that he used in effecting this test 
the unboiled bricquette at three days gave a tensile strength of 714 lbs., aijd the boiled bricquette 
at three days gave qyo lbs. tensile strength. Whether that had a connection with the soundness 
or the unsoundness of the cement he was not prepared to say at the moment, but he felt that the 
accelerated test was not only one which should be used for the acceleration of the tests in the cement, 
but also to show the acceleration of the strength. 

He had to express his indebtedness to .Mr. Butler for the most excellent paper which he had given. 
He was sure that he (Mr. Butler) had not suggested that they should leave boiling tests at the present 
moment without some very good reason, and until they did get a test which would satisfy the use 
of the cement to improve its soundness he thought that they must adhere to the boiling test. 

MR. F. T. TRISTRAM. 

He had carried out a great many experiments with the Le Chatelier test, and there was no doubt 
it was very variable, but all tensile and other tests were the same. It was largely a matter of the 
personal equation. He would like to mention first the elasticity of the moulds which Mr. Butler 
referred to. He also had found out there was a slight variation there : in fact, he had got a mould, 
an excessively useful mould, which he would not part with for anything. It invariably showed less 
expansion after boiling than when the original measurements were taken. 

Expansion. His experiments had been more with the intention of trying to find out what was 
the action of boiling water on the cement, which frequently caused expansion in an apparently other- 
wise perfectly sotmd cement. He thought there were various reasons for the expansion indicated by 
the Le Chatelier test. Firstly, by faulty manufactured, overlimed, or badly calcined cement, but 
he always found in those cases that aeration would cure it ; secondly, in a well-manufactured 
hard, burnt cement, which might be due to increase in volume ; thirdly, by the cement being slow 
setting and not hardening sufficiently before being boiled. 

When one came to deal with a cement which, for instance, he used for his experiments, which 
gave 9 mm. expansion at first, and after aerating for 24 hours, 7 days, and 14 days, still gave the same 
expansion of 9 mm., he maintained if that had been caused by the presence of free lime the expansion 
would have gone down. Then he started to %vork on the grit to see to what extent it was responsible 
for the expansion. The cement which was rotary was quite normal in composition, was ground, leaving 
14 per cent, residue on the iSo sieve and all other tests satisfactory. First he examined the grit under 

281 



THE CONCRETE INSTITUTE. 



[CQNCRKriLi 



1 f .,,,,,1 it wa^ entirely composed of verv hard, dense, and partly fu^ed partKle^. Tliere 
a ""-°-°P; -"'J°™t'\;\::: ^o^^^^^ half burnt. In order to trv and find if there was any expansion 
was no trace an> where in t^ gri o a ^ ^^^^^ repeated tests, gave no expansion 

in^the grit itse« ^^ *™^\^^,.^;;""^';^i^/;:ttn;w\o J Mr. Butler made his experiments, but he found 
whatever on the Le Chatel en ^^^' ^ d^„,, ,^^3, „„less something was used. 

t::siTzr:z t'.=r;rri« «»' .,. .,. .0... » »- ~n*.,o„ o.. ,«.. 

'"''°^' u- ,f >,,.! fonnd that as a rule, a well manufactured cement would not crack a test tube 
uiitn ; :r;ch c' fom ^o ' ; mnt. exp'ansion on the Le Chatelier test, but he would like to have 
"me expression of opinion from Mr. Blount or Mr. Bntler on this important point. 
MR. C. H. WATSON, Assoc.Inst.C.E. 
,, He had always been an advocate for the Le Chatelier test from its inception or really 

mer^nn': tteSln^loL ti^oTetble, and'that one could record it : that altogether it was an .x- 
'-^-::':::;i;:rtnfess that his exp.ien..c.it.^ 
^I-;j:::::^^lT^::£tin::^^^ -t, .ere cmte capab. of 

calledphysicalconditions-thatistosa> that the rna^ j , ^^^^ ^^ ^^ ^^^^^^.^^^^ ^^ ^^ 

was a slow-setting cement and a slow ^e tin .me^^ . ^ ^^^ ^^.^.^^ ^^^ ^^^ ^^^^ .^^ 

mcursion of water into the sample, vvireii t- larsrelv to the phvsical condition 

took place at that time, before being P -^^ 'n o h s o as due^ argeU to th p .^^ ^^ ^^ ^^.^^ 
of the incursion of water into that sample, and he did not tlnnh il 

the soundness of the cement whatever. n„„,tion of whv thev got expansion with the 

. ^^^ -'^%"rh™.re c m'e":it''^ l^aTer fi e^ ^ein^rwl ^s^d, well,%hen,'they got a close 

grit as against the very fine cement ii a _ prevented, and also the expansion 

consumers. ^^ LAWRENCE GADD. F.I.C. 

.e««o-.-The first Point he wished to refer to was^NI. Butler's ^^^^^ ^^^^^l^:^ 
aeration, when he mentioned that a curious feature ^l?^'" '';%;^;J^f ^n the cem-nt was aerated, 
were verv frequently met within which 'he expansion became greater v hen the c^m ^^ 

He gave 12 fairly recent samples in which this ^f t^^en p ace. f ^^'^^^^^^^f ^/if,,! pubUshed an 
that! because he had seen cases of that sort literally ^v scores, and as a^ ^ tueve Th^' i" ^^^ ^^J°"'>' 
article on this very test, in which he said that his "P^"-^^^ ''^f^'l'^^.f "^° ^/J,'^ '„„ and he mentioned 
ot rotary cements as then manufactured the expansion would ^^^ ^^;V fbetw en 3 and 12 mm., which 



(^'vLnojn^fS'n?:'-] the LH CHATHfJHR liOIIJNG TF.ST 

stnaycia iL-<imiciiii-tUs ot the consumer's tests, and In- did not lind ttic iiicnsi-;p of expansion on aeration 
nearly so frequent nowadays as a few years ago; but at the same time he thought everyone who had 
much experience in this Le Chatelier test must come across instances now and then, at any rate, even 
tu-day, where on aeration a larger expansion was obtained than before. 

Expansion In Cold Water.— .•\nother important point was expansion in cold water, raised last Mjiy 
in this room by Mr. Bamber, .ind which was perhaps of m^rc importance than ths expansion in bjiling 
water, because it came more nearly to the conditions in actual practice, although it ought to be 
remembered that in actual practice cement was rarely used neat, and the expansion practically dis- 
appeared when the cement was mixed with sand. His experience contrary to that ot the last speaker, 
led him to conclude that expansion in cold water was nearly always due to the presence of calcium 
sulphate, generally in the form of gypsum or plaster, and he thought it was due almost entirely to the 
formation of sulpho-aluminate of lime, as first pointed out by Caudlot. 

Another speaker had mentioned that although sulphate of lime had a tendency to cause a certain 
degree of expansion in cold water, it appeared to reduce the expansion when the cement was after- 
wards boiled, and he could quite endorse that. Some few years ago he carried out a series of experi- 
ments on nearly 200 cements, and had plotted the results. The curves obtained showed an ahmst 
symmetrical relation between the proportion of calcium sulphate and the Le Chatelier expansion 
figures. In some cases an am.iunt of calcium sulphate, equal to 2 p:r cent, of gypsum, reduced the 
expansion in boiling water by 6 or 8 mm. 

With regard to the author's remarks on the expansion of the coarse particles, these were especially 
interesting to him, because he thought he was the first investigator to point out the influence of fine 
particles of grit on expansion in th° Le Chatelier test ; but Mr. Butler appeared to him to have lumped 
together the whole of his residue on the iSo-mesh sieve, and called that grit ; and he also called flout 
or 6ue material, everything that passes through the iSo-mesh sieve. But he (.Mr. Gadd) had shown 
previously that the larger particles of residue— that is to say, residue which is retained upon the 76-mesh 
-levo, had no influence whatever on the expansion. It did not make any difference whether you 
11 ived them from the cement or put them in ; these larger particles did not cause the expansion. 
particles which did cause the expansion, which did the damage, were much smaller particles, 

ir of which would pass readily through the 180-raesh sieve, and were not all retained except on a 
mosh^of something like 240. The author did not offer us any explanation as to why these particles 
should cause expansion, but he (Mr. Gadd) in the Engineer of September iith, 1907, had offered aa 
explanatii'ii which might possibly be the true one. 

MR. J. F. PLAISTER. 

Expansion In Cold Water.— \ point_wluch had not been raised was in tonnection with the ex- 
pansion in cold water. .He agreed with Mr. Watson that that was really a physical defect in the test. 
He had made many experiments with the sam? cement, with gypsum and without gypsum, and he had 
found where it expanded in the cold water without gypsum, that with the addition of a certain amount 
of gypsum it did not expand anything like so much. He put that down a great deal to the nature ot 
the cUnker from which the cement was ground. He thought m jst mrinufacturers who ware acquainted 
with the rotary system of burning clinker would bear him out that at times it varied very much in 
toughness, dependent a great deal on the nature of the fuel used to burn it ; and what he found was 
that where a very tough clinker was used one got the greatest expansion in cold water, and he put 
tliat down more to the fact that there was not the same aniount of flour in cement ground from tough 
cliidier, and therefore there was a larger absorption of water after the mjuld was placed in the 
tank and there was a sort of miniature volcanic action set up during the boiling process. It was most 
remarkable that directly you put something in the shape of flour, it did not matter whether it was 
gypsum or anything else, into cement made from that class of clinker, you reduced the expansion in 
cold water. He had made some 300 or 400 tests on those lines, and they all confirmed the sams view. 

MR. W. L. H. ROBERTS. 

.Manufacturers would endorse that the better the clinker, the finer tlie clinker; but the harder 
the clinker, the more difiicult it was to satisfy the Le Chatelier test. When the clinker was moderate 
and did not carry quite such a large tensile strain, it would _easily pass the Le Chatelier test ; but 
when they got the very finest clinker that could possibly be produced, then the Le Chateher test 
began to give trouble. 

As an instance of the mireliability of the Le Chatelier test, a friend had sent them some clay from 
AustraUa, and asked them to sample this clay, and see whether it was fit for cement making. He was 
not prepared to say exactly the composition of that clay, but at the same time it looked very good, 
somewhat high_in silica. They mixed this up with their own chalk and burnt it in the ordinary 
sample kihi, such as a great number of the manufacturers here probably used, and tested it ; there 
was not enough of it to make tensile or other experiments, but there was enough to make a pat for 
the_boiling Le Chateliertests. The pat after boiling showed no curvature, but was absolutely brittle, 

283 



THE CONCRETE INSTITUTE. [ CQNCBETE] 

and could be broken up with the greatest ease, the result of the Le ChateUer ; we could hardly measure 
the amount of expansion that occurred. 

He had always found that the Le Chatelier test was a very useful one as an indication for the 
manufacturer, but was no guide as to the value of cement, and only gave a perfectly false impression 
to the users, as they did not really understand what it meant. The real test for^the soundness of cement 
was the pat immersed in water for 28 days, after w^hich time it should show no signs of curvature or 
flying, and should be quite smooth and sharp. The Le Chatelier test was an accelerated one, and as 
such, should not condemn a cement if it were shown to be otherwise sound. 

MR. BUTLER. 

The Lecturer's Replies. Mr. Butler prefaced his reply by expressing his thanks for the favourable 
reception given to his paper, and his gratification at the excellent discussion it had evoked. Replying 
first of all to the Chairman's remark, he said what he wanted was a test which would detect real, not 
imaginary, unsoundness. The primary function of a soundness test was to detect unsound cement — 
viz., cement which would cause expansion under practical working conditions. A test which condemned 
sound and unsound cement indiscriminately could not be a true test for soundness. 

Mr. Bamber said it must be a bad cement, indeed, that would not stand the Faija test for soundness. 
He maintained in connection with the Faija test that what unsoundness the Faija test would not 
show was negligible. Regarding practical results, if a cement did not show any expansion in the 
Faija test, that cement would not show any expansion whatever in actual work. He was glad Mr. 
Bamber agreed with him that the Le Chatelier test should not be too rigidly interpreted ; when, as 
the discussion had shown, there were almost as many anomalies as orthodox results, it was a test 
that should be accepted with some reserve. 

Mr. Nicol referred to boiling his test specimens for .48 hours. His own experience was that, if 
there was no expansion shown after six hours boiling or less, it would not show with longer boiling ; 
six hours was quite enough in the ordinary way to show all the expansion there washkely to be. Mr. 
Nicol also referred to the importance of the w-et grinding during manufacture as ha\'ing an important 
bearing en soundness, and he quite agreed with him, but Mr. Xicol rather seemed to confuse the two 
^)rccesses of wet grinding and dry grinding. He (the authori was fully aware that wet grinding was 
quite as important as dry grinding, but when Mr. Nicol referred to wet grinding he obviously confused 
it with dry grinding — i.e., the reduction of the cUnker and not wet grinding, which was reduction of 
the raw material. Mr. Nicol referred to his own accelerated tensile test, which was one day in air and 
two days in boiling water, and which he specified should show 30 per cent, higher results than one 
day in air and two days in cold water. The lecturer did not think any manufacturer would object 
to that, provided the cement would stand boiling water ; but, as he had said before, it had yet to be 
proved that because cement would not stand boiling water it was therefore unsound. 

Mr. Tristram's remarks as regards his microscopic experiments were very interesting. He men- 
tioned that he used a matrix with his grii, consisting of i6§ of fine cement to make it set. The 
lecturer found no difficulty in making the grit set in the Le Chatelier mould. Though soft, it set 
fairly well, although boiled out sometimes. 

Mr. Watson suggested that many of the anomahes mentioned in the paper^werc capable of e.xpla- 
nation, but he rather carefully avoided giving any. Mr. Watson's admission that some of the results 
he had himself obtained with the Le Chatelier test varied as the barometer had done in the last few 
days was rather significant, and tended to confirm the experience of a good many other operators. 

Mr. Gadd reported his contention as to the increase of expansion on aeration, and said he could 
quote instances by scores. The lecturer could also, but only gave two or three in the paper just as 
examples. 

Mr. Plaister referred to expansion in cold water. As they all knew, the old test for soundness 
used to be simply immersing a pat immediately after gauging in cold water, in the plunge pat, some- 
times called " sudden death." That test was more or less a delusion. In the first place it was only 
neat cement that showed such cracks after immediate immersion. He had made many experiments 
with cubes and pats made up of sand and cement ; when they were plunged into water immediately, 
they showed no expansion, and if they did it was merely on the upper surface or skin, perhaps j*s in. 
deep. It was purely surface cracking, and did not penetrate to any depth beneath the surface, there- 
fore, in his opinion, it was negligible. 



284 



^ 



REINFORCED CONCRETE ROOFING. 



NEW WORKS IN CONCRETE 

AT HOME AND ABROAD. 

Unaer this hijdinil re'i.ibU infornuition 'Will td presffttt'J of nt"ii> ivorks in course OJ 
construction or completed, and the examples selected tvill te from alt parts of the "world. 
It is not the intention to describe these works tn detail, but rather to indicate their eiistence 
and illustrate their primary features, at the most explaining the idea tuhich served as a basts 
for the design. ~ED. 



ROOFING AT ST. ALOYSIUS CHURCH, GLASGOW. 

UiiiNi <)i.:i i;i) ciiiuTi'li construct-on is tjaiiiiiif^ fiivour with arcliitecis for the construc- 
tion of churcli roofs, llic princip.il adv.intaiJfes being the practicibility of constructing 
large barrel and domical roois uilliout unsightly trusses, tie rods, etc., and the low 
cost of upkeep. 

An interesting example of this form of roof, and one of the first to be constructed 
througliout of reinforced concrete, is that of St. .\lovsius Roman Catholic Church, 
(ila-gow. 

The reinforced concrete work was c.irried out by the Expanded Metal Company, 
l.iiniled, of London and West Il.irtlepool (who are represented in Scotland by Mr. J. 
.Monkhouse C.artmell, of 69 Buch.man Street, Glasgow), to the general designs and 
under the supervision of the architect, Mr. Chas. J. Men.art, of Glasgow. 

In pl.in, the church is of the usu.il cruciform shape, and the building is faced 
with red freestone in the classic style, the reinforced concrete roof work being carried 
on llie main walls. 

The roofs over the nave, transepts, and apse are in the form of semicircular 
arclies, the nave roof having a clear span of ^4 ft. 6 in., and a length of 65 ft. The 
nave roof is supported on arch ribs, reinforced in such a manner as to take the 
whole of the stress due to thrust without putting any thrust on the side walls, where 
the load is vertical ; the ribs carry a 4i-in. slab forming the roof covering, this slab 
being reinforced with Exp.onded Steel. There are two 4-light cupolas in this roof, 
wliich art al^o t; vonlilatnr>;. 




Expanded steel-concrcle roofing. 
St. Aloysics Church. Glasgow. 



28; 



NEW WORKS IN CONCRETE. 



[COSCBETEJ 



The roofs over the transepts and apse are of somewhat similar construction, but 
of smaller span. Three of the main arches, carrying the large central dome, are of 
brickwork; the central dome, which is ^4 ft. l)y 34 ft. 3 in. on plan, has a radius of 




29 ft. 6 in. for the first portion, and a radius of 21 ft. for the upper portion or dome 
proper; there are eight large lights in this dome. The concrete in the dome is 

286 



A 



coNynJiiiTioNALt 

LN(il»i:.LKlNCi ~J 



RKISl'ORCED CONCRHTI-: GALLHRIHS. 



t;ciuMally i) in. lliii-k lliroiiyhoul, rcinforcoil with cx|).iik1c(J sicel, and circumfcrtntial 
roiLiHl stfcl rod rinses. 

'I'lio sa>lu>s in all ilic roof liglils are of \vrou),'lii iron secured to the concrete, and the 
roof is covered with aspliah. 

The interior will eventually be finished in a decorative style, for which reason its 
stirface \v;is left fairly roiii,'h with the object of fonnini,^ a " ke\ " for |>laster or 
mosaic. 

THE NEW REINFORCED CONCRETE GALLERIES AT HULL CATTLE MARKET. 

Int. adaptability of reinforced concrete is |)erh,i|>s Jiowhere belter illustr;>tcd than in the 
new ,y;alleries at the Hull Citlle MarUet. Kroni the photo-graphs and dra\vin}.;s 
illustrated, it will be seen (hat it has been successfully used in the various units of the 
constructions, inckidinsj foundations, columns, beams, cantilevers, lloor decUinfjf, 
bridges, and screen walls. In none of the parts are the dimensions excessive or in any 
way displeasing to the eye; in fact, when compared with the old galleries, which are 
constructed of concrete arches between rolled steel joists supported on cast iron 
columns, the advantage of appearance certainly rests with the new galleries. 

N'o. I Gallery is tod ft. long and h.'is an average width of ^i ft. No. 2 Ciallerv is 
1.^7 ft. bv 2\ fl., .and No. ;, ("..lUerv 142 ft. by 21 ft. ' 




The most interesting features of No. i Gallery are undoubtedly the large columns 
and cantilevers supporting the centre floor panels, shown oh page 289. It was desired to 
use the space beneath this gallery for two large cattle ]X)unds, and the arrangement of 
a central column with cantilevers supporting the jxiints of intersection of the longi- 
tudinal and cross-beams of the gallery was adopted as the arrangement which gave 
the greatest clear space. The drawing of one of these columns clearly shows the 
construction and also the disposition of the steel. The close hooping of the column 
and cantilevers indicates the high duty which was successfully imposed on them. 

The designs of Galleries Nos. 2 and 3 were somewhat similar, the main difference 
being the spacing of the columns laterallv. This resulted in a difference in length 

28: 



A^£U' WORKS /A' CONCRETE. 



[CONCBETEJ 



of the cantilever b.am. suppctin,^ the .creen walU. which can readily be observed fr.n. 
""' Thf otdal testin- took place on December 31st last, and consist^ of loading 

''"tiTe^grrtesHp^ntf Gallerv No. t was .3 ft. 3 in., .md -he n.aximun. deflection 
re-istered was 0-021 in., equal to . 5^5^ of the span. 




Details of screens, showing reinforcement. 
Nos. 2 and 3 Galleries. 



^^^ 



* 



•. — \-=r^^=z^ 






Details of main longitudinal beams, showing reinforcement. 




Detail section of No. 3 Gallerj . 
Hull Cattle Market. 

,, ,..,,-, nf n-dlerv \o ', was 2^ ft., the permissible deflection 0-5 in. 
Ihe maximum span ot Liaiier\ -no. ^, u.l. -0 > i- 

and the maximum registered deflection o'lo in., being ^i,-. of the span. 

288 



[J, lON^ I pm-nciNAi,l 
■v l,N(ilNt:i£.lflN<i — J 



RlilSrORCI-:!') CONCRETE GALLERIES. 





NEW WORKS IN CONCRETE. 



ICDNCRETEJ 



As these tests were considered most satisfactory the eii.t;ineer decided tliat it was 
not necessary to test Gallery No. 2. 

To cope with the increased capacity of the marlcet a new entrance and slope were 
constructed to give access to the new galleries. The illustrations show this part of 
the works and also the columns supporting the landing. 

The works were constructed to the designs and under the supervision of the 
British Concrete-Steel Co., of Cathedral Buildings, Newcastle-upon-Tyne. The rein- 
forcement used was that of the Patent Indented Steel Bar Co., Ltd. 




9 61 «o- 

Detail of coiiimn and cantilever beams under No. 1 Gallery. 



NEW CANAL BASIN AT BRADFORD. 

The canal basin in our illustration is an arm uf the Leeds and Liverjxiol Canal, 
situated at Strangford, on the Esholt Estate, within the City of Bradft>rd, and adjoins 
the large and important sludge disposal works which are now being erected. 

Concrete construction was employed throughout in the walls of this basin and 
also in the bottoms, which were made 6 in. thick. 

The basin is 133 ft. 6 in. long, 45 ft. wide, and the bottom is formed in two equal 
bays of different depths. The depth of water in the back bav is 6 ft., and that in the 
front bay at the entrance is S ft. 6 in. This extra depth of 2 ft. 6 in. over the front 
half of the basin is important, and is provided for the reception of silt, which is found 
to collect somewhat rapidly. The basin is capable of accommtxiating four of the 
largest boats in use on the canal at the present time. 

The canal itself has been widened and deepened on both sides at the basin 
entrance. These works have been carried on, without hindrance to ordinary canal 
traffic, by means of timber sheeting driven into the bed of the canal to form cofferdams. 

Concrete face walls have been constructed for a considerable length on both sides, 
providing further accommodation for four canal boats. 

The basin is watertight. .-\s all the stone and sand necessary for concrete was 
found on the site the works have been economically carried out. 

The works were commenced early in June last. The basin was tilled with water 
on October 22nd, and was formally opened for traffic on January 4th. 



290 



r j.CXSN.vreiKTlClNAlJ 
Lev LNaiNLEKlNt. ~J 



CANAL BASIN. 



The works, which included a considerable amount of excavation and I'dling for 
the formation of yards around tlie dock and a lentllh of new roadway, were carried 





out by adniinistratiivn, the chief engineer being Mr. Joseph Garfield, Assoc.M.Inst.C.E., 
and the resident engineer, Mr. W'ontner-Smith, Assoc.M.Inst.C.E. 

29 I 



NEW WORKS IN CONCRETE. 



[CQNCBETFJ 



FLOORING AT THE TECHNICAL INSTITUTE. BELFAST. 

The illustration herewith is of tlie tlooriiiij at tlie Technical Institute, Belfast. 
The spans in this instance were 20 ft. in the clear, and tlicy are now carrying a work- 
ing load of 2 cwt. 

The construction consists of a series of concrete webs, which are reinforced with 
a patented section of steel bar. Small tubes are fitted between the webs and a thin 
layer of concrete laid on the top. 




View of Flooring. 

Our illustration shows how this system of flooring can be laid without centering, 
and also demonstrates the freedom of site given to the builder for the progress of his 
work. 

The flooring througliout this building was laid by the .\rmoured Tubular Flooring 
Co., of Victoria Street, .S.W. 



292 



r J. I'ONM PIK-nONALl 
l'>.HN(.lNt.blJlNl. —J 



REINFORCED CONCRETE MANHOLE. 



NEW USES FOR CONCRETE 

AT HOME AND ABROAD. 

Under this he jjing reliable information ivill be presented js to neiu uses to which concrete 
jnd reinforced concrete are put, with data as to experience obtained during the experimental 
stage of such new applications of these materials. The use of reinforced concrete as a 
substitute for timber in exposed positions is one of the Questions of the moment. Rail-way 
sleepers, telegraph posts, fence posts, etc., of concrete are being tried. Similarly, efforts 
are at present being made to prove that reinforced concrete is an excellent substitute for 
brickwork, -where structures of great height are required.— ED. 



REINFORCED CONCRETE MANHOLE. 

Till-; accoiiipanyinj^ illustrations sIkiw a reinforci-d loncrete manhole, ust-<J In 
draining the main line of the Midland and Great Northern Joint Railway. 

It is necessary, at every three or four chains, to place a manhole, so that the 
piix's can be inspected and cleaned out if necessary, and in the ordinary way this 
means sending a bricklayer perhaps live miles from a station and carting bricks 
and cement some distance. 

The great advantage, therefore, of the reinforced concrete manhole described here 
is that it is made at the depot, and can be put in without skilled labour bv the ordinary 
draining gang. 

The illustration below shows the manhole with the drainage gate on the top, 
which was designed by Mr. Alexander Ross, M.Inst.C.K., .ind used on the Great 
Northern Railway. 




Concrete Manhole. 



293 



NEW USES FOR CONCRETE. 

A REINFORCED CONCRETE COAL 
POCKET. 

A coal pocket, embodying" a rather 
unusual combination of brick and rein- 
forced concrete construction, has recently 
been built for the L. S. Starrett Co., Athol, 
Mass., from designs by Charles T. .Main, 
mill engineer and architect, of Boston. 

In plan, the pocket is triangular, 
being 150 ft. by 109 ft., and about 30 ft. 
high. The walls are of brick, within 
which is built a concrete steel shell or 
lining. This relieves the former of the 
pressure of the coal, and at the same time 
serves as a protection for the brick wall. 
This lining is built directly against the 
brick walls, e.xcept at one corner, thus 
saving the cost of form work on the outer 
side. 

The brick walls are 12 in. thick, with 
integral pilasters 20 in. in thickness. The 
concrete steel lining is carried up 20 ft. 
Two 15 in. by 33 lb. channels, back to 
back, spaced about 23 ft. apart and 
embedded in the concrete e.xcept on 
the boiler-room side, connect with the 
longitudinal and transverse channel bnices 
overhead, thus binding the parts subjected 
to the coal pressure firmly together. On the boiler 
above-mentioned vertical channels are set into the 
vertical " I " beams varying in size from 7 in., 15 
the latter are concrete slabs 54 in. thick, reinforced 
steel wires. The concrete around the wall channels 
by metal lath reinforcing. .\11 steel work is protected 



ICQNCBETEl 




I^EiNFOKCED Concrete Manhole. 

-room side of the coal pocket the 
brick walls. Between these are 
lb., to 12 in., 3 1 '5 lb. Between 
with both horizontal and vertical 
and " I " beams is held in place 
bv at least 2 in. of concrete. 




r^ 



F.N(ilNt.LI<lN(. 



ri-:im-()Rci:d concrete coal pocket. 



Two rows of sU'cl i-oIiiiiins, s|),u-c'il iS 11. apart in a transverso direction and 
23 ft. () in. apart lonijiludinallv. connect willi the ovcrlu-ad channel braces and supjxjrt 
the lonj.;itiidinaI roof beaitis. 'I'he.se columns, of square section, are made up of 
ani^'^les latticed to form an " I " beam section, and are encased in concrete up to a 
heiijht of 1^ ft. 'I'he concrete at tlie corners of each colimin is reinforced by steel 
rods. 

'llic roof is supported 1)V tile bricl< w .ills .and columns, the concrete lininjr c.-irryin;^ 




pone of the weig-ht. Diagonal steel tie rod bracins,', with turn buckles, is used in 
conjunction with the columns, and connection is made thereto by clevis nuts, wired 
and covered with 2 in. of concrete. Up to a height of 15 ft. these rods are encased 
in boiler tubes with cement between. The floor is of concrete, g in. thick, finished with 
trowelled surface. We are indebted to 77ic Cement As^e for our illustration. 



295 



NEW USES FOR CONCRETE. 



[CONCRETEJ 



WATER TOWER AT GREAT MARLOW. 

Thi. water tower ^^as conMruct«l in reinlorced concrete on the Hennebique system 
bv Messrs. Holloway Bros. (London), Ltd., for the Great Marlow NVater Company. 

^"'J^^::^l?:!^:^r5?^uare on plan with sides 5 i^. thicU,. .o ft. .on^ 
bv Q f t 6 rhi^h (inside measurements), while the top level, of corn.ce beam, .^ 
.n ft 6 in above the Sfround level. It is carried by four corner coluinns, square in 
tec ion each il in bv 14 in., and reinforced with four bars linked together m the 
u'u^rwav The eo of the column terminate in foundation slabs, b ft. square, 





Decorative Centrepiece erected at the Annum 
Cement Show in Chicago. 

ogether. hpijrhts of 10 ft The lower bracing consists of four 

The CO umns are braced at heights ot 10 it. n c ^, ^ j j 

296 



ti 



IIQNMUIK'IIONAI.I 
F.Nr,lNI:.LKlN<. ^j 



DECORA Tl VE CENTREIUECE. 



hr-Ac\nii was oniittwi. The columns were continued up the sides of the reservoir lo 
form corner counterforts, while between them, at the level of the bottom of the tank, 
were four main beams 12 in. wide by 18 in. deep, carrying the outside walls of the 
tank and also carryinjj four subsidiary beams which, in their turn, carry the I'loor of 
ilic tank. These subsidiary beams were 7 in. wide by 15 in. deep, and the floor 5 in. 
thick. The side walls, 5 in. thick, were each further slrenfjthened by two counterforts, 
5 in. liv b\ in., rigidly held at their tops by the cornice beam previously referred lo, 
and were thus constructed as vertical floors. The side walls were also braced bv four 
beams 7 in. wide 12 in. deep, each connecting opposite walls. The reinforcement in 
the walls consistL^i mainly of i|-in. vertical bars and A-in. horizontal ones. 

DECORATIVE CENTREPIECE FOR THE CHICAGO CEMENT SHOW. 

.\ conipclilion was ori;.irii><'<l in .\nierica for the desi)j;n for an orjiament.il centre- 
piece to be encii-cl ai the Third .\nnual Cement Show, held at Chicago in Kebru.ary 
la>l, and a l.irgc nuinbrr of ino-t interesting and attractive designs were submiltetl. 




The centrepiece was to be of either plain or reinforced concrete, concrete blocks or 
cement plaster, and it could be finished in any manner which would produce a pleasing 
effect. 

The design chosen for the first prize was coinixjsed of a gigantic pedestal orna- 
mented with figures in relief supporting a shaft some 35 ft. high. The top figure was 
re-designed, that which was eventually erected representing a powerful youth, and 
is ty-pical of the cement industry. The four sides of the base are decorated with 
plaques, the upper part being a shield and the lower being a design representing the 
four ages of mankind — the Stone, Bronze, Iron, and Cement .Ages. 

We also show an illustration of the design which obtained the second prize, 
and which represents a very attractive fountain, 25 ft. in height. 



Z9; 



M EMORANDA. 



[CDNCBEnEj 




........ ... .^sn..s ^;^l^:^'^t./ti^ ^S^-^—' ^" 



rests Of t.e '^einforce.Con^et.SU^.-^.tAc.e^n.^ 

'°"'''V0 \ M-in. bv ivin. (octagonal) horizontal strut was loaded under a ^yeight of 
,i tins placed in -the centre, the distance between the supports bang .9 ft. The 
'^' T?" c^pS b^^otoi^n cross-fran.ed decUin,^ was loaded as follows.: 20 tons 
weriliiirS^^ong the Centre keel bean^.o in^ JV^^J '"O^f ^ Tl'sl^ . 

(•>o in. bv 18 in) a deflection of less than -^ m- ^^ '^^ re^isiere^. 
T:'elrc;;rwL'S°lT°/.S™, «, ,ecorJ.d under , he ,eM .o,„l. t..e be»,„ 

nature were not considered necesv.u\. , . ,, ,.^„, 

communication with the compressed '"' .P P;.^"j'.^°""'"j:°ded against in this method 
line bv a funnel-shaped outlet. 1 he chief thinR to '^e f "''[f ° ^^^- ^^ ^^^^ the rapiditv 
of handling concrete is the clo,^s.ng of the =°f -t.^"' " The idea cetainly deserves 
of transmission would "Aviate any tendency o the Un^^^^ J^^n ftles of concrete have 
a trial on some important building contrac ^f";^^ '=^^^",^f j^.^^^ ayvanta^re would be 
to be delivered froii. the mixer to all part of J^^ f ^^^^^ ^'^..■'^^ation of ^he mixture 
the avoidance of delavs -h.|:h are lkel> to cause partia^ .^ ^^^^^^^^^ 

and to encourase partial setting ot the cement. i ne 4 R„;;,f„ > 

of course, comes in, and must be decide.1 by expenence.-(7;,. Budder.) 



m 



iricjNxn MHMORA NDA . 



Building a Concrete Cistern. — An improve hilmU in the metlKKl of construitins; a 
ccnRiu cistc-rn, ovit llie ])lan ordinarily reconiniunded, was reci-iillv observed by a 
conteni|X)rary on an Onlario farm. Tin* metlio<l usually adopted of luiildinf^ an uprifjlit 
circular wall and covcrinj^-arch at one 0|)eralion involves the taUinjj out through the 
manhole of all the curbing as well as the timbers sup|X)rting the arch. In this case. 
after the circular \v:dl had been linishe<l to the top of the curbing, it was allowed time 
to set sulliciently, and then the curbing was all taken out. The supporting frame for 
cement arched cover was m.ide by cutting six or eight short rafters, with slight heel 
projection, resting on inner edge of perpendicular surrounding wall, and tops meeting 
over centre of cistern. A wooden box for ;i m.inhole was set in position, the remaining 
space on the rafters bo.irded over, and the cement covering spread on the desire<l thick- 
ness and shape. When safe to do so, in about .i week, the roof structure was easily 
removed from the inside, only a very few n.-iils having been used. 

Tests on the Permeability of Concrete. — The University of Wisconsin has issued 
a bulletin on the al)oM- -.ubject by Professor Francis .Michael .\lc{"ullough, Instructor 
in .Mech.mics. The bulletin comprises a re|X)rt of a series of ix-rmcibility tests made 
in the laboratory for testing materi.ils at the L'niversily of Wisconsin during the 
summer and autumn of HjoS. The object of the tests was to determine the elWciency 
of some of the commerci.d com|K)unds used for the waterproofing of concrete. 

Tests were made on fourteen compoimds, each compound being subjected ordinarily 
to pressures of .ipproxim.-Uely 20 lbs. in.- ;md 40 lbs. /in.-' The duration of the test 
w;is usu.illy three days, ;md a ri'cord was kept of the amount of water entering the 
concrete. 

In order to .ascertain the effect on the strength of concrete of the compounds which 
are .added to the body of the concrete, compression si)ecimens were made. Three of 
the compounds were tested in this manner, the sjx'cimens being broken at the ages of 
approximately one, two, and ten months. 

.\mong other conclusions, it is st.ited that, unless extreme care is taken in propor- 
tioning, it is necessary that some form of waterproofing be used for a 1 :}, 15 concrete 
for pressures from 20 lbs., in.- to 40 lbs. in.- 

Kor nearly .ill specimens the r.-ite of flow decreased rapidly with time. This was 
especially m,arkc<l in Ihe case of the mort.ar coatings, and was due in part to their 
dry condition. 

Placing Concrete under Water. — riiere is undoubtediv ,1 strong prejudice in the 
engineering profession against Laying concrete under w.ater. .Millions of pounds ;ire spent 
every year, according to The Eiigiiiecriiii^ Record, on colTer-d.ims and caissons, in order 
to lay foundation concrete in the dry. Notwithstanding this, it is entirely possible to lay 
concrete under water which will be as sound and solid as the best concrete laid in the 
open air. In the construction of the Detroit Tunnel a large .amount of concrete was de- 
posited around the submerged steel tubes. .\ core from this concrete, which had been 
taken to determine its quality, was recently examined. The core was as sound and solid 
as a natural conglomerate rock. Tests of samples of this concrete have shown a strength 
as high as, or higher than, the best s[)ecimens of concrete laid in the ojx^n air. This 
concrete is de|K)sited through a tremie, or long tube with its upper end in the open 
air a consider;d)le distance above the water surface, and its lower end at the point 
where the concrete is to be laid. Concrete put in place by such methods is forced in 
under a pressure far greater than is possible with any hand ramming ever used. There 
is no space for voids and no opjxirtunity for the entrance of air. Furthermore, the 
concrete is never dried out in the process of hardening, and has always available all 
the water that it needs for its final set. These reasons are all of importance in 
explaining the high quality of concrete laid in this way. 

.At the recent convention of the National .Association of Cement Users, Mr. Olaf 
Hoff also referred to the method of using tremies for depositing concrete under water, 
and gave what he considered the reasons for its success. First, the exterior of the 
tunnel tul>es is divided into compartments or pockets by means of the longitudinal 
sheathing and the diaphragms. This produced still water, which is absolutely neces- 
sary for laying concrete under water, and |>ermitted the filling of one pocket at a 
time with a monolothic mass of concrete. This arrangement further limited the 
lateral flow of the concrete, as it emerged from the tremie, to the confines of the 
pocket and reduced the washing out of cement to a minimum. In fact, the loss 

299 



CONCCETEX^^''°'^''^"''™^^^ 



E3*<rGITSri:ERrNG 




UNIVERSAL JOIST STEEL 

SHEET PILING 




USED BY 

ADMIRALTY :: :: 

:: :: CROWN AGENTS :: 

Messrs. EASTON GIBB & SON. Lid. 
Messrs. WALTER SCOTT & 

MIDDLETON. Lid. 



USED BY 

:: Messrs. JAMES BYRON. Ltd. 

:: Messrs. S. PEARSON & SON :: 

BELFAST HARBOUR BOARD 

GREAT WESTERN COLLIERY 

DICK. KERR & CO., Ltd. 



ALL TYPES OF PILE DRIVING PLANT 



SEND FOR CATALOGUE. 






^holograph 


sho 


ws 


15-m. b^ 


4) 


-lb 


P.lmg ,n us 


e on or 


eof 


twelve 




Cofferda 


ms 


bei 


ne 


construe 


ed 


lo 


a Viaduct 


over 


the 


River 


Loughor 


bv 


Me 


«rs 


Walter 


Scott & Middleton 


Ltd. 


■lh€ 


Piles 










w.ll be us 


ed 


IX times. 









"GR.A MERCY. 
LONDON." 

TELEPHONES- 
P.O. 1414 Central. 
Nat. 1414 Avenue. 



DOCK HOUSE, BILLITER STREET, 
LONDON, E.G. 



ntion this Journal ■ 



.- -WAl.l 

LNtiiNHKiNi, ~J MhMORANDA. 

..I cvmvin ..piKaivd to be nefflisible. Second, the equipnieiU was vcrv complete, and 
llK' nij: for liand in.i,' ihe treinie pipes was esix-cially quick acting, s6 that the pipes 
could be inanipulated promptly as occasion required. 'l-hird, the concrete was mixed 
so u.t lb.,1 .1 would I ow readily in the Iremies. Fourth, the llow was controlled bv 
Ueepin;^ llu- nunilh of the treniie buried at all times in the concrete to a sullicient 
depth to l«c p 11 M-al.-d and prevenl water from rushing in from the outside. 

Municipal aad Health Exhlbltlon.~lhe second .Municipal and Health Exhibition 
IS .innouncixl to U- held at the Royal .Vgricultural Hall, Islington, from Mav - to 
May 14. Such exhibitions are designed to make known the most ellicient methods 
ol street cleansing,, street paving, the economic utilisation of refuse, public lightini/ 
traction, the housing of the vvorking-cl:,sses, and the construction of public buildings' 
Ihe forthcoming exhibition will be uniler the patronage of a large number of lord 
heuteiianls, lord mayors, and mayors; and an .idvisorv council h.is been formwl of 
nuinicipal surveyors and engineers throughout the Inilcd Kingdom, with Professor 
I lenry .\dams as their Chairman. 

The promoters of the exhibition hope to achieve two objects-(i) To interest and 
instruct municipal ofticmls ; and (2I to educate the public in the municipal services 
U|>f.n which the rates are exix-nded. The exhibits will be divided into two main 
cl.isses -public works and internal administration -and thev will illustrate Ihe details 
ol the construction of town halls, public libraries, hospitals, schools, asvlums work- 
men s dwellings, bridges, and markets, and the laving out of public parks and 
cemeteries. 1 here will also Ix.- exhibits in connection with public sanitation traffic 
(ro.ic and river), municipal ambulances, municipal telephones, smoke abatement water 
supply, and fire prevention. The Incorporated .Association of .Municipal and Countv 
hngineers has arranged to hold a meeting at the exhibition, at which paix-rs will 
be read upon topics suggested by the exhibits. It is proposed to give technical lectures 
HI the afternoons and [xipular lectures in the evenings upon questions of kx-al govern- 
nunt, and facilities are to be sought to enable the municipal officials to visit public 
works in London. 

Irish Road Congress. -\n Irish Road Congress is to be held in Dublin in April 
next in connection with the Spring .Agricultural Show of the Rovat Dublin Socictv. It is 
proposed ih.it ,a the same time as the Congress there shall be .-in exhibition of road 
making and repairing machinery and implements, and applications for space therein 
should be made to the Secretary of the Royal Dublin Society, B.-ill's Bridge, Dublin. 

.\mong the subjects on which it is hoped that pajxrs 'will be submitted to the 
t ongress are : Ihe maintenance of trunk roads; State contribution towards road main- 
ten.ince; laws relating to opening roads, laving pijx-s, etc.; extraordinarv traffic, light 
railways and tramways on roads; formation surface, foundations, drainage, and super- 
structure. Also bridge work and reinforced concrete construction, various qualities 
ol road materials, direction posts, etc., dust nuisance, economv of even surface etc 
I he Secretaries to the Congress are Mr. .\. Keogh Nolan, 10 Leicester Street, Dublin 
and Mr. K. II. Dorman, County Survevor, Armagh, from either of whom lists of the 
committees, programmes of the Congresses, etc., may be obtained on application. 

Resistance of Concrete to Gun Fire.— The resistance of concrete to gun fire was 
testwl practically to some extent at Port .\rthur, savs E,iiiinecn„i: Record and different 
opinions have teen expressed regarding the lessons to be drawn from the results 
there. In a general way, the objections to concrete have been based mainlv on the 
claim that the efTect of the impact against it was to crack such a large mass of material 
that the integrity of the structure was much weakened even bevond the immediate 
vicinity of the point of impact. Reinforced concrete has been suggested a number of 
times as a substitute for mass concrete in militarv works, in order to meet this 
objection, and some tests were recentiv conducted at Sandy Hook for the purpose of 
determining to what extent the reinforcement would limit 'the effect of the projectile 
Ihe results are of a confidential character, but it is understood that the success of 
the reinforcing rods in confining the shattering of the concrete to the immediate 
neighbourhood of the pathway of the shot through the mass was marked, \\-hile 
the steel did not api)ear to reduce greatlv the absolute depth of penetration of the pro- 
J«:tile, It localised the damage very satisfactorilv, so long as the shells did not detonate 
after penetrating. 

301 



MEMORANDA. 



[CQNQ3ETEJ 



Reservoir at Lon Biggins. — Thf Kirkliy Lonsdale U.D.C. have adojjted the 
Surveyor's alternative schemes for the construction of a storage reservoir and the 
necessary alteration of mains and services in order to improve the water supply to 
Low Biggins, the scheme providing a storage capacity of four days' supply being 
estimated to cost ;£^ioo, and that for seven days' supply ;£ji4o. The Council have 
resolved that tenders be invited for the work connected with the seven days' supply, 
the prices being obtained to show the respective cost of a concrete roof to the reservoir 
and of a corrugated, galvanised iron one with surrounding fencing. 

TRADE ANNOUNCEMENTS, CATALOGUES, ETC. 

W. J. Fraser & Co., Ltd., of 98 Commercial Road, London, E., send us an 
interesting' booklet descriptive of the " Trump " concrete measuring and mixing 
machine, for which they are the Manufacturing Agents in Great Britain and the 
Colonies. The principal advantage claimed for the " Trump " over the ordinary 
mixing machine is that it can be set to give any particular proportion of cement, sand, 
and ballast required, and, when once set, is locked, so that the engineer or clerk of 
works knows that the concrete is being made in the exact proportions which he desires. 
The importance of uniform and continuous measuring is dwelt on, and the measuring 
device of this machine is described and illustrated in detail. The " Trump " portable 
concrete measuring and mixing machine is a self-contained outfit, and when equipped 
with the portable conveyors requires no erecting expenses. The concrete machine and 
the convej'Ors are hauled separately to the site of the work; one end of the conveyor is 
raised so as to rest upon the top of the concrete machine, one chain is connected up, 
and it is ready to start. The source of power is permanently mounted on the same 
frame, and may be gas, electric or steam. 

The (U.K.) Wiaget Concrete Macliine Co., Ltd., of Xorthumberland Street, 
Newcastle-on-Tyne, have appointed Mr. T. Percival Chubb, of Bowley Street, London, 
E., as their sole .Agent for London and the Home Counties for the sale of their 
well-known " Winget " ro)icretP lilock-making machine and thrii- " F.xpress " concrete 



^=()ig§^SCi 



A NEW PROCESS 

FOR FIXING IN REINFORCED CONCRETE 
FLOORS, ROOFS & WALLS, WHETHER 
STRAIGHT OR CURVED, BY A SIMPLE METHOD, 
WITHOUT THE USE OF SHUTTERING 

This process considerably cheapens the cost of 
the concrete construction, and is indispensable in 
districts where there is a scarcity of timber. 




y. 'j^ y > 







CONCRETE 

AND 

CONSTEUCriONAL ETSGINEERING 



Volume V. No. 5. London, May, 1910. 

EDITORIAL NOTES. 



REGULATIONS FOR REINFORCED CONCRETE. 

Till') aiticli- on " Rct;ul;itions for Reinforced Concrete liuiklinj^s in 
London," which appeared in our last number, has led to a considerable 
amount of correspondence reachintf us on the subject of public control. 

riic pressure on our space prevents our fjivinyf the correspondence the 
publicity we should like, and \vc ha\e had to limit ourselves to publishing two 
letters, one from a well-known civil ent^ineer, the other from the manager of 
a representative specialist tirm. 

The matter is one of great importance to the development of reinforced 
concrete in this comitry, for, as we have indicated on earlier occasions, we 
hi}ld that the careful regulation of reinforced concrete ^would inlluence the 
sound development of this material, and prevent the set-back to be expected 
in the event of any serious accident occurring in the I'niied Kingdom. 

We take this opportunity of calling attention to the standard building regu- 
lations for reinforced concrete which have been suggested by the National 
.Association of Cement Users of the United St,ates at their recent convention 
in Chicago. 

A copy of these regulations appiars in this issue, and, coming as they 
do from those who really use the material, they are worthy of careful 
attention. We are glad to observe that the .\merican cement users have 
tormulated their own \iews in such a precise manner. 

To all who are interested in the subject of regulations for reinforced 
concrete we cannot, however, do better than refer them to the article on 
" Regulations and Recommendations for the Use of Reinforced Concrete as 
Published in Various Countries," which appeared in our Journal in July, igo8, 
and which gave a very compact summary of the rules and regulations that had 
been issued by the various cou-itries, all the clauses being tabulated under 
leading headings, which makes it very handy for reference purposes. 

THE CONCRETE INSTITUTE VISIT TO PARIS. 

The Concrete Institute, which has been giving considerable attention to the 
question of the rusting of steel embedded in concrete, is making careful 
inquiry as to some of the older examples of reinforced concrete, or their 
equivalent, in this countrv and abroad. 

3°3 



THE CONCRETE INSTITUTE. 



[ CONCRETE) 



In connection with these investigations it is of interest to us to learn that 
the Science Committee of the Institute has extended its personal investigation 
to the Continent, and that a visit has lately been paid by several of the members 
of the Institute to France with a view to obtaining knowledge of some of the 
earliest examples of reinforced concrete to ascertain the durability of this 
material. 

France is obviously the home of reinforced concrete, and it is onlv fitting 
that Paris should be visited in connection with work of this kind. 

A short account of the places visited is given under " Memoranda," in 
this number, but we hope to be able to puljlish more detailed particulars at a 
later date. 

The following notice has been issued by the Institute to the Press : 
The deputation of members of the Concrete Institute have returned from Paris, 
where they have been making a special inquiry into the durability of reinforced 
concrete. For this purpose, visits were paid to about a dozen important structures 
in and near Paris, including bridges, culverts, tunnels, reservoirs and buildings, all 
of reinforced concrete. These were of various ages, the oldest being the roof of 
a large house constructed no less than fifty-eight years ago by the late M. Coignet, 
whom many consider to have been the first inventor of this material. 

The programme of visits was arranged by Professor Rabut, the Chief Engineer 
for New Works of the French State Railways. The deputation were specially 
invited to dine with the Association des Ingenieurs des Ponts et Chauss^es. In 
the absence of the President, the visitors were received by M. Colson, Membre de 
Conseil de I'Etat, a former Inspector-General of this distinguished corps. 

The visitors were also hospitably entertained by the Chambre .Syndicate des 
Constructeurs en Cinient arme, whose President, M. Edmond Coignet, is a son 
of the famous inventor, and by .M. Hennebique, whose reputation as a designer of 
reinforced concrete is world-wide. 

The deputation consisted of: Sir Henry Tanner, l.S.O., F.K.I.B.A. (Principal 
Architect, H.M. Office of Works); Mr. William Dunn, F.K.I. Li. A. ; .Mr. F. A. White 
(Chairman of the .Associated Portland Cement Manufacturers (1900), Ltd.) ; Mr. A. 
Ross, M.Inst.C.E. (Chief Engineer Great Northern Railway); Mr. C. H. Colson, 
M.Inst.C.E. (.Admiralty); Mr. W. G. Kirkaldy, A.M.Inst.C.E. ; Mr. J. S. E. de 
Vesian, M.Inst.C.E.; Mr, F. E. Wentworth-Sheilds, M.Inst.C.E. ; .Mr. E. P. Wells, 
J. P.; Mr. H. K. Dyson; Mr. H. K. G. Bamber, A.Inst.C.E., F.C.S. ; Capt. Gibson- 
Fleming, R.E. ; Mr. G. C. Workman; Mr. P. W. Leslie; Mr. H. H. D. Anderson, 
and Mr. P. M. Eraser, .A.M.Inst.C.E. 

It is understood that the deputation were well satisfied with the results of their 
inspection, which will form the subject of a special report. 

THE WATERFORD BRIDGE. 

It is with great pleasure that we hear that the almost interminable con- 
troversy regarding this bridge has now been definitely settled by the authorities 
in question specifying a reinforced concrete bridge, and the necessary order in 
Council, together with the requisite specifications, have been approved. 

It will be remembered that this was a case where advocates of a more 
expensive steel structure used all their power and influence to avoid the cheaper 
and more serviceable material being used, and the victory for the advocates of 
reinforced concrete is certainly a most important one. 



r J.CON.sri'm-MON'All 
L'v t Nf.lNH I^IM, —J 



FACTORY AT 11 A YES. 




REINFORCED CONCRETE 
FACTORY • AT • HAYES. 



f-r^-'-T?f'T:fTp^'-T-^^^^Cn:?^ 



U I .j-i ,^!jj to jgjin tc able to gine particulars of a "very im orlant hitldtng being 
crccleJ in rfinforced concrete, as il Is a striking example of the ad-vantages thai material 
affords for ivork of this character, —ED, 



()\n of the most important undcrtakinj^s in reinforced concrete construction 
erected in this country forms the subject of our article, and should prove of 
i^real interest to our readers owinij to the maj^^nitudc of the work, which is 
plainly seen in tlie drawinsjs and phototjraphs in our illustrations, as well as 
heins,'- a iioleworthy example of the practical use of reinforced concrete for 
factoiy construction. 

Tlie buildini,'- is one of the Orchestrelle Company's new factories at 
Hayes, Middlesex, put up by Stuart's (Iranolilliic Company, and two more 
blocks ■j'/c, the music roll factory and the stencillinjf buildin<j — are in course 
of construction by this lirm, and we hope shortly to be able to give an 
account in our cdlunins ol these buildings, together with photographs and 
details of tlie work. 




Second floor. Pianola building. 
Okchestrelle Company's Factory. HAVEsi^ 



305 



REINFORCED CONCRETE. 



[CT^CBETEl 



The block of buildings here described consists of : — 

(a) The Pianola factory, which contains four floors and a flat roof. It is 
193 ft. long and 48 ft. wide. The floors are designed and executed to sustain 

View r.f p anola building. Power House, and Drying Room building. 




^IT 




*■ 



m 





JiiiHilil 



mmm 



Pianola buildii 



a safe loading of 3 cwt. per foot of surface; the roof is designed for i'50 cwt. 
The floors are covered with Stuart's Patent Granolithic laid at the same time 
306 



m 



FACTORY AT MAYES. 



as ihv ruiiilornd concrotc work. The roofs arc fiiiisliccl uilli asplialte as a 
wcathcr-prool co\ criiii,"'. 

(1)) Till- powrr liDii^c, (■(Hisislini^ ol tuo lloors and Hat roofs at (lilTcrcnt 




Pianola Building. Tliird Floor during; conslruction. 
Orchestrelle Company's Factorv, Hayle. 

levels. This building- is 80 ft. by 80 ft., particulars of which are shown in 
the drawing illustrated on page 311. The floors were also designed in this 
case to carry a safe load of f, cwt. per foot of surface with i'5o cwt. for 
the roof. 

c 307 



REINFORCED CONCRETE. 



[CONCBETEJ 




308 



f J. lON.VrBUCTlONAU 
L'v li.NI.INbt:.BlNI. — J 



FACTORY AT HAVi-JS 




309 



REINFORCED CONCRETE. 



ICQNCRETEJ 




310 



J, lON.vnJUlTlC/NAlJ 



FACTOR Y AT HAYES. 




REINFORCED CONCRETE. 



[CONCRKrLi 




312 



r J. ClON.vrUtH'llONA 1 .1 

^«EN^■lN^.^:RlN(. — ^J 



FACTOR Y AT HAYFS. 




First Floor, Pianola Building's. 
Orchestrelle Companv's Factoky, Ha 



4:^^' V^ 



313 



REINFORCED CONCRETE. [CONCRETE] 

(c) The drying-room building, measuring- 49 ft. by 41 ft., and having 
two floors. In this building Messrs. Stuart's GranoHthic Co. have installed 
a most ingenious system of reinforced concrete slab walls, made up of graded 
thicknesses of stone and joggled and jointed, and having bevelled slits for 
the passage of the air which is required for the drying of the timber used 
in the Orchestrelle Company's productions. The system of drying, we under- 
stand, is a patent one, and we cannot therefore give particulars or details of 
the process employed. 

(d) The coverings of ducts tiirouglK)ut tiic several buildings and in yards, 
approximating to some 800 ft. of varying widths. These are made sufficiently 
strong to take the loading and traffic that will circulate upon them. 

Almost all the floor space on the solid groimd is covered with Stuart's 
Patent Granolithic Paving. 

The framing of the Ijeams and columns is shown bv the accompanying 
plans to reduced scale. The prevailing idea was to lia\c the buildings sup- 
ported by reinforced concrete columns resting on similar foundations and then 
to fill in between the panels with brickwork. 

The whole offers a most pleasing result of the combination of brickwork 
and reinforced concrete, and to all those interested in adopting these materials 
it is well worth a visit to Hayes to inspect this factory, as the building is 
extremely artistic as well as most practical. 

The work was originally designed for steel girders, joists, and concrete 
floors, but the architect ultimately decided on having a reinforced concrete 
structure, which has appreciably reduced the cost. 

As above mentioned, Messrs. Stuart's Granolithic Co., of Fenchurch 
Street, were responsible for the reinforced concrete work, Mr. E. P. ^^"ells, 
their consulting engineer, preparing the working drawings. Messrs. Fryer and 
Co., of Paddington, were the general contractors, and Mr. Walter Cave, of 
Old Burlington Street, W'., the architect, to whose design and under whose 
instruction the whole of the work has been carried out. 



3 '4 




'JUANTITIES A\D ESTIMATES. 



1 



QUANTITIES and ESTIMATES 
for REINFORCED CONCRETE. 



Hy H. KEMPTON DYSON, C.E.. 
I echnical Secretary, Concrete Institute. 



/'; view uf the grejt nec£S:iily for the sUnJarJisulion of methods for reinforced concrete 
•work, 'We think an article on the preparation of Estimates should prove of interest, - ED, 



In the February issue of this journal an article was published relating to 
standard methods for the preparation of reinforced concrete drawings, in which 
the author referred to the advantages to be obtained from the adoption of 
standard methods of executing drawings submitted with tenders for reinforced 
concrete work. Detailed consideration of the subject was there given, with 
suggestions of ways in which labour could be saved by the general adoption of 
such standards. It was stated at the conclusion of the article that standard 
methods in the drawing office had a relation to standard methods in the pre- 
paration of estimates, and also in the execution of work. We may now 
consider this latter aspect of standardisation. 

To classify details of the work for consultation by the draughtsmen, the 
estimating staff, and, at a later stage, the executive staff, is but an adjunct to 
the work of design. It seems a general custom to prepare schedules of the 
sizes of beams and columns in tabular form, giving particulars of the sizes of 
the reinforcements in each part of any design. In the United States, in con- 
nection with steel-frame buildings, the scheduling of sizes and quantities has 
arrived at some measure of standardisation, and the author suggests the 
adoption oi tabulated statements conforming generally to the .Xmerican 
standard scheduling. 

COLUMN SCHEDULE. 

In tall structures it is customary to reduce the loads on columns or pillars 
from those adopted in calculating the floor slabs and beams. This is based on 
the idea that it is quite impossible for the entire floor in every storey of a 
building to be loaded to the maximum at the same time. The Joint Committee 
on Reinforced Concrete appointed by the Royal Institute of British Architects 
has suggested certain rules as regards the amount of reduction of the floor 
loads on colunms. These, in short, were simply that the roof load was to be 
taken at the full ; that the live load on the storey below the roof was to be 
reduced by lo per cent. ; the live load on the storey below that another lo per 
cent. (i.e.. 20 per cent.) ; the storey below that another 10 per cent, (i.e., 30 per 
cent.), and so on until the reduction of the live load on any particular floor 
amounted to 50 per cent. 

In tall structures with many floors the column loads are made up of several 
separate items, each varying in amount, and, in order to minimise the risk of 
error and omission, it is very desirable that the loads should be detailed in 
some tabular form of statement, which would act almost as an automatic 
check. In such a schedule the loads transferred through the columns down to 

3'5 



H. KEMPTON DYSON. 



ICONCBETEJ 



the foundations should be set out in detail, so as to show the gradual accumu- 
lation of the load. In skeleton or frame construction the column loads include 
floor and live loads, wind loads, spandrel and pier loads, the weight of the 
columns themselves and their fire-resisting or decorative covering, and, in some 
cases, special loads, such as tanks, strong rooms, safes, lifts, etc. In tabu- 
lating the floor-slabs also it is not only important, with a view to a reduction 
of the loads upon the columns, to separate the total load into dead and live 
loads, but as affecting the design of the foundations, for as a rule these are 
designed to carry only a small proportion of the live load. In very tall struc- 
tures the wind loads also need to be considered, both for designing the columns 
and for dimensioning the foundations, though in buildings not exceeding 
loo ft. in height the wind loads are generally disregarded. It is also important 
to tabulate separately the eccentric loads on columns, because the matter of 
eccentricity in the loading is often disregarded, whereas merely a small amount 
has a consideraljle effect in reducing the strength of a column. In the follow- 
ing column sheet, which is suggested as suitable for ordinary purposes, it will 
be noticed that the total load of each storey is the sum of all the loads above. 
FORM OF COLUMN SCHEDULE. 







Column No. I. | 


Column No. 2. 


Sti.rcy. 


^^ 


Conccn trie 

Load 
on Column. 


Eccentric 
Load on 
Column. 


Concentric 
Load on 
Column. 


Kccent ic 
Load on 
Column. 


7th Storey 


Roof and ceiling, dead load 
Roof and ceiling, live load. . 

Beams 

Spandrels, cornices, etc. . . 
Brick nr stone piers 

Walls 

Lifts 

Tanks 

Column and casing 

Wind . . 












Total 











Sectional area required 


in.» 


in.' 


6th Storey 


From column above 
Floor and ceiling, dead load 
Floor and ceiling, live load 
Beams 

Spandrels, cornices, etc. . . 
Brick or stone piers 

WaUs 

Strong rooms, etc. . , 
Column and casing , . 
Wind 












Total 












Sectional area required 


in.= 


in.« 


Basement 


From column above 
Floor and ceiling, dead load 
Floor and ceiling, live load 

Beams 

Spandrels, cornices, etc. 
Brick or stone piers 

Walls 

Footpath 

Column and casing 

Wind 












Total 










Sectional area required . . . . in.* 


iD.« 




Deduce (i) live load ., .. ' 1 


1 



Foundations 



Total foundation load 
Area of foundation required 



OUANTITIHS; AND ESTIMATES. 



SCHEDULES FOR MATERIALS. 

W'c now coiiii- to ihr question ol schedules tor in;itii'i;ils. I k-rc, again, 
\vc obtain help from the same standaiclisecl methods adopted in the United 
States in connection with structural steelwork. On the foUowing^ page is the type 
of tabic suggested. It will be seen that in the diagrams showing how the rods 
arc to be bent and otherwise tlealt willi angle measurements are not stated, 
but only the general lengths and distances to which the reinforcements are to 
be worked. This is much more accurate and more convenient than attempting 
to work to angle measurements, especially in the shops, for the great point is 
that the steel should secure a close connection with the other reinforcements 
which may not be detailed on the particular schedule given to the workman, 
and if he had to work to an angle measurement the merest fraction would 
throw the work out. No templates or setting out upon the floor to full size 
are required by this method. By scheduling the reinforcements in this way 
it will be found generally that the steel can be fabricated in the shops more 
economically than upon the job, though this is not a hard and fast rule, and 
it is often more advantageous to execute the cranking and bending of the 
reinforcements in close proximity to the work. Such a schedule, with the 
omission of some of the particulars relative to bends and cranks, and the dia- 
grams relating to same, will also ser\c in connection with preliminarv drawings 
supplied to an architect or engineer. 

QUANTITIES. 

Krom the schedules pro\idcd with a preliminarv drawing and the general 
drawing, showing the construction, the quantities are taken out, and the 
detailed working or shop schedules can be prepared more or less as an elabora- 
tion of the quantities ; therefore, in taking out these latter, it w ill be found 
economical of time and generally advantageous if they are drawn up upon some 
system whereby assistance is given in the preparation of the detailed scheduU-s 
of materials at a later stage when the work has been secured. In the method of 
taking out quantities for reinforced concrete, naturally one would expect to 
conform to general practice in respect to quantity taking, but there is a 
difference in the fact that in this s\ stem of construction the reinforcements are 
so numerous and contain so many labours that the ordinary method of quantity 
taking is very tedious and can neither he checked nor got out so easily as where 
a method of tabulation is adopted. Some constructors have adopted such 
tabulated statements for quantity taking, and the one appended hereto, in 
the author's opinion, meets all recjuirements. It is, perhaps, rather elaborate, 
but it is of the greatest assistance in the estimating to have full details provided. 
The quantities supplied by many specialists at the present date are not nearly 
sufTiciently detailed to enable close estimating to be effected. It is quite 
inadequate to price up steelwork at so much per ton, including all labours, 
because the latter \ary so very much. Attempts have been made to average 
such work, and sometimes a portion is taken out in detail to give a basis for 
pricing per ton, but unless it is taken over a large quantity, and the work is 
exactly similar in character, the system of estimating by averages may err very 
greatly — on the one hand the prices may be far too little, on the other hand 

317 



H. KEMPTON DYSON. 



iCQNCKETEJ 




thuy mav be too liii;li. In the Rr^t 
case the profits made will be much 
reduced, and, in fact, in some cases a 
loss sustained ; while in the latter event 
the estimate may be too hig-h and the 
work be lost. 

It is, perhaps, too early yet to say 
that there is any recognised system of 
quantity taking for reinforced concrete. 
The quantity surveyors, as a pro- 
fession, will probably say that there is 
notbing new in taking out quantities 
for such work, that the ordinary 
methods that have been adopted for 
steelwork and fire-resisting' floors may 
be employed for reinforced concrete. 
Specialists in the latter material, how- 
ever, generally think otherwise. 

In taking' out cjuantities by any 
method soiiie system must be observed, 
and the only items in which there 
seems to be any established custom are 
(i) that the floor-slab should be taken 
over the whole area of the floor and be 
taken as the same thickness through- 
out as it is between beams, and (2) 
that the depth of the beams, although, 
strictly speaking, extending from the 
soffit to the top surface of the con- 
crete of the floor-slab, should be taken 
as onh' from the soffit of the beams 
to the underside of the floor-slab, 
riie correctness of this policy may 
be doubted, because where top rein- 
forcements are provided in beams 
these are placed in the portion of 
concrete usually counted as part of 
the floor-slab, and the labour of 
placing same cannot be counted as a 
percentage on the total area of the 
floor-slab. Also, if we price the 
concrete in a beam at so much 
per foot cube, say, then we must re- 
member that we are omitting, in taking 
the size of the beam, a certain amount 
of concrete which has already been 



[^.-^jTi^'^j]"^ QUANTITIES AXD ESTIMATES. 

t;(ki'n in the llooi-sl.ih !)\ the customary method. Hovvever, perhaps this is 
not so \cry ser'ous, thoni;h theoretically objectionable. I'he labour of putting 
these steel reinforcements in place is not so very great, and where there is 
considerable amount of top reinforcement the estimator can make a sufficiently 
accurate allowance. .\s, in estimating, the price of the concrete should be 
varied according to llie thickness of the floor-slab, it is important to have the 
concrete in the floor-slabs stated in square yards of a certain thickness, and 
not in yards cube, as is often done. 

The centering for the tloor-slabs is usually taken over the whole area of 
the lloor, though here, again, it would be more correct if the extent of the 
beams were deducted therefrom ; however, the extra area is not of much conse- 
quence, as, if this be recognised as the custom, we can assume that tills extra 
allowance of material covers the cost of fitting to beam boxes. 

As regards beams and columns, one often finds the quantity of conciete 
stated at per yard cube, but it is more convenient to state it in feet cube. The 
size of each beam and column should be detailed and the feet run of each 
particular size may, with advantage, be stated, as the price must be jirupor- 
tionately increased for beams and columns of small size and small quantitv. 
.Any labours to beams and columns, such as chamfered edges, etc., should be 
detailed separately at per foot run, both in concrete items and in boxing items. 
In taking the girths of the boxings no allowance is usually made for the thick- 
ness of the boards, and the quantities should be stated in feet super. Small 
work under 12-in. girth should be stated separately at per foot run. 

As regards the quantities of steel, it is a question as to whether this should 
be stated at per ton, per cwt., or per lb. The tendency at the moment seems 
to be in the direction of stating the quantity in tons, but as the weight is 
generally taken in pounds some contractors prefer to price the work at per lb., 
thinking that thereby labour is saved, but as the lb. is such a small unit the 
price cannot be so closely varied as is thought desirable by some estimators. 
Sometimes, for instance, work is priced at iJ[d. per lb., on other occasions, 
when this price is not considered sufficient, i jd. is adopted, and then again, if 
this is not sufficient, the next price that will be put down is r|d., or again, 
\kd. These prices, it will be noted, amount respectively to ;£,io los., 
;£.'ii 13s. 4d., ^,"12 Kis 8d., and ^,14 per ton. It will be seen that the 
difference between each price is considerable. On the other hand, the objection 
that is raised to using a ton as a unit is that not only must the quantities be 
converted, but they often amount to less than a ton, so that when the amount 
is stated in tons the total tonnage may be very small. Indeed, for any par- 
ticular work, the quantity of steel rods may often not even amount to a ton. 
The conversion from pounds into some other unit the author thinks is 
advisable, but the objection to using the ton can be counteracted by employing 
the cwt. as a unit. This is convenient, too, because the price per ton at which 
we buy the steel, and from which the estimator is accustomed to build up his 
price mentally, can be read immediately in cwts. by taking the pounds as 
shillings. 

It is important to detail the size of these reinforcements as well as to give 
weights, because manufacturers charge different prices for rods of different 
dimensions, small rods being often more expensive than the larger sizes. 

3'9 



H. 


KEMPTON DYSON. 






yUANTlTIES. 








ICONCRETEJ 

FLOOR AND 


WALL 


LOCATION. 

o 1 1 


CONCRETE, 


CENTERING. | 


OS 
dS 


.J 

ft, 
8 

10 
6 


,5 
g 

ft, 

8 
10 
13 




5 ■? ■S 


1 


C 


° S 

zP 


5 
c 




en 


(..round; 
1 )o. j 
I-'irst 


A 
B 
C 


6 
4 
10 


n, ft, sup. ft. sup. f 

4 

5 

3 1080 

gnoso 9 

= 120 
yds. sup, y 


, sup. 
384 


ft. sup. 


:t, sup, 
100 


ft. sup. f 




6 
4 
10 


ft, 

8 
10 
6 


ft. 

8 

10 
18 


ft. 

384 

100 
1080 

9^1564 

= 17377 
yds. sup. 


;384 


9noo 


=42'66 


= 111 
yds,5Ul 




j 


' ^'r'^ L ™ ' 


1 




- 1 







BEAM 


LOCATION, 


„ i STEEL 
CONCRETE. CENTERING, |^ 


il 


^6 
1^ 


^1 
Zh 




*i,n 
II 

am 


Cubical 
Contents 

No. of 
Times 1 


Length 1 
1 Girth 

Superfi'I 
Area 


zSa 


.5 

J 1 

ft, in. 
16 8 
19 8 
11 8 
16 10 


1 * 

1 * 


IT f 


a .5 
t, ft. 


ft, in. 
46 8 


ft in " •" 1 f 


(.'.round 


G1G7 


I 2 


ft, 
16 


24X9 


ft, 
48 


2 


ft, 
16 


57 


ft, 
152 


2 
4 
4 
2 


78 8 


33 4 
33 8 


II 


46 8 
X 1-502 lb 


78 8 67 
X 2'044 lb. X 2'67 lb. 


27M8 
= 178 


9J152 




1 


= 16'< 
yds,su 


1 I 

P.l ! 1 


= '627cwt 


= r44 cwt. =r6 cwt. 


BlL 


D TO j 




' 1 






1 




COLUMN 


11 ^i-xi-rcclisir . LONGITUDINAL STEEL ROUS. 
, nr ATlON.i CONCRETE, Ij CENTERING. ^ __ ^ _ ^ ^ 


8 


c 
u 


6^ 
ZH 


K 


t:c75 


Cubical 
Contents 

l^N^oTof'" 
1 Times 


X 

t, in 
6 

9 8 


Girth 

Superfic'l 
Area 

No, of 
Bars in 
Columns 

! Length 


Is 

(/) 


c 

ft. 

360 

360 
x-667 lb. 


ft. ft 


ft. 


E 4 

ft. ft. 


ft. ft. 
480 

480 
X4'1731b. 


Grount 
First 


Gl- 

Fll 


10 
i 10 


ft, 

11 

10 


14x'l 
10X1 


ft, in, 

150 10 

) 69 5 10 
27;219'5 


56 
40 


490 
322 

9;812'0 


40 
40 


12 
9 


yds. 


8-13 




=90'2 
yds. sup 


' 




' 


=2'14 


cwt 


1 




= 179cwt. 



r Q. cnNyreucTioN A u 

L^ENGINtXBlNCi — J 



QUANTITIES AND ESTIMATES. 



LAB SCHEDULE. 











MI'Et. I< 


)1)S. 






\i MUKK 


OF Besds 


NUMUKK ( 




Wire 



















Ac Ckasks is Rods. 


Ends to Rods. 


TVINOS 


VU) 


tM 


jg 





















u 

■^ 


z"* 


« 
^ 


II 


_o 




'♦• 


a 


.E.2 


.S.S 


.S.S 


iz 


1 


in. 




ft. in. 




fl. 


ft. 


ft. 


ft. 












1 6 


% 


S 


9 




768 










192 






1 U 


4« 


12 


s 




576 






192 






;768 


' t 






H 








800 








160 

192 




1 5 

Ul 


96 

72 
40 


14 
U 6 
18 


' 


6120 


720 


1344 




2880 


384 




|360 
■ 140 










6120 


i06+ 


1344 


800 




















X 167 lbs. 


X 375 lbs. 


X 667 lbs. 


XI 043 lbs. 














1 1 c«t. 


=6'92 cwt. 


=802 cwt. 


= 745 cwt. 


3072 


384 


288 


352 


126S 



CHEDULE 



RODS. 


NuMUbR Ol 


Uknds 


NtMUliROl-HoOKEl. 










& Cranks i 


•< Rous. 


Ends to Rods. 


1 KsDS TO Rods. 




STIRRUPS 




.S 


I'l 


4 




CT 




C'7 


in. to 
t-.n. 
n. to 


-d 


II. to 

n. to 
-in. 


■= =5 1 


N C 






1 






m, 


"" 


TST"" 


'S~.'S 


■•» 


n* "df 


-^'" - "' 


■^ ^h ^ 




2-€ 


ft. 


ft. ft. 


ft. 


ft. 








1 








in 


in. ft. in. 


ft. in. 




1 








— 










2 


r 


4 63 


t 


21 
























— 


Link 


10 


63 


52 6 

























— 


Lini< 


8 


62 


ixA 




41 4 
















1 








Link 


b 


65 


i 


33 6 


































106 


41 4 
































X 167 lb. 


X-212 111. 














































24 








22 1 


' 








1 ="158 cwt. 


= 078 cwt. 


























'^— 


— — 









•!> Links 
I- Spiral 



321 



H. KEMPTON DYSON. [CPNCRClQ 

In the schedule it is fairlv easy to record the labours in sufficient detail 
without much trouble, and therefore the objection that is raised to givmg these 
labours-namelv, that the time for getting out the quantises m the prehmmary 
sta.es of tendering is insufficient-is met, and the dissatisfact.on olten occa- 
sioned bv the estimator having to approximate the cost per cwt. from^ an 
inspection of the drawings can be avoided. It is suggested that sufficent 
detail is -iven bv recording each reinforcement connected w>th each beam and 
column Stating the number, sizes and sections of the main bars ; the number 
of all cranks, 'fishtailed or bent ends in the bars of each section; Ihe number 
and size and character of each reinforcement, each stirrup or tie, the number 
and size of anv top reinforcing rods, and, finally, detailing all special labours 
separatelv. From the form of schedule here provided, the manner m which this 
can be done without incurring much trouble and without taking up too much 
time is clearly shown. The total quantity of each particular item is obtained 
bv adding up each column. Such a schedule is very easy o reference after- 
wards if it be desired to check any particular part of the work 

In detailing the reinforcements in floor-slabs it is desirable to state the 
number of the rods and whether these are laid direct or in meshwork arrange- 
„,.nt, also the number of bent ends should be recorded, and the number and 

si/e of the cranked rods. , . ■ ,, • ^ 

^s it is advantageous to be able to estimate the cost of wiring the intei- 
sections of reinforcements arranged in a meshwork. for a great deal of money 
s often spent upon such apparently small items, therefore it is desirable tha 

he estimator should be provided with some data in this respect. The weigh 
of wTre is not. as a rule, furnished, and. of course, ,t is not exactly a simp e 
matter to asceitain this with any great degree of accuracy but the size of the 
w-'e can at least be specified, together with the number of mter-sec ions 

equired to be wired per unit of area or length-/..., per square yard m floor- 
stab or per foot run in beams and columns. The approximate amount of 
wring"ecessary can be ascertained by taking out a small portion, adding up 
The number of wired intcr-sections, and then multiplying over the whole area 
or total length. 



322 



SaT] 



RMIAVA y COXSTk'L'CTia.N 



- ' ■ fe " - ^ -H-'ilitin iiviji 

^^^^^Xy^' REINFORCED CONCRETE 
rM::.;,^'^'-^=-^-/ RAILWAY CONSTRUCTK 



«,//-! ',','r'' '!;"'■""'' "" ';'' '^'"f'"^" '^""CKlf for rj,l-uuy ■u,ork /Ui i-«„ ,„.,J,. ,„ XrT„Ta- 1 //Mn ,n 



STATIONS AND PLATFORMS. 

A cu,.M ,unni..,- of ,1,. A.n.-.ican railways hav.- utilised o.nrretc in ,hc con- 
slau..,,,,, .„ Ma,u.ns o, all kinds, and . lu-re no, adopt.-d for tin- entire structure 
. .s l...,uen,ly used lor a portion of the work, such as platforms, foundations. 
.stancas.s, smoke duels, and platform columns. It is easily adapted, has the 
K.eal ady^mtaKcs ol ,ue-resis,in^ qualities, and is permanent, while the illus- 
.•a„on ol ^ ara.hon s.atlon. F,,. ,o. shows that it is capable of architectural 
treatment ,, no n.ean ord. , . This struCtn-e is a combination passeno,r 
stat.on an.l lrc.,,h, house, and, xyith the exception of the roof, the buildin-. 
.s ,,l concrete construction throughout. The foundations and main walls are of 
pla.n concrete, the only reinforcement employed consistitijf «f three ^-in. square 




323 



RAILWAY CONSTRUCTION. 



ICDNCKETEJ 



,od. near the soffits ol all lintd, over square openings wh.le the floors and 
^a:for,.s are of plain concrete laid directly on a cinder ^^^^^^^ ^f^^f ^^ 
^.ranolithic ti in. thick. The lower parts ol the walls arc tool hn.sh.d. uh e 
'he npper parts are hnished by floating the concrete w,th wate, .u.d 
rubbing witi wire brushes immediately alter the lorms are removed. I he 
whole of the con.-rete was mixed in the proporoons ol , part Portland cem nt 
To wts sand and 4 parts of broken stone. Plath.rms have been constructed 
n 'plain concrete for many years past, but the adaption ol h,gh pla lorms on 
"pd transit and sul>urban lines n. more recent tin^es has led to the use of 
reinforced concrete as being more economical. • j • , the 

\ tvpical ground platform constructed in pkun concrete, mixed m the 
p,.op;H-tKi of r part Portland cement, , parts sand and o parts broken stone. 




is that illustrated in F,V. :>, which is a photograph ol Lohoes station and 
1 tm X Y.C. and 11. R. Klv. These platforms are usually constructed 
'io ft long and ,. ft, wide and are divided into blocks of not more than 
lo so ft area. The surface is usually hnished with granohth.c, m.xed .n 
the pl^oportions of . part Portland cement to ^ parts of -"d. ^ any o^ the 
new train sheds on the American railways are qmte a departure Irom the 
hitherto considered standard type of structure for th,s purpose. - ^^^ o^ 
comprising a series of high arches, which in the common type o t.am shed 
a'continttallv enveloped in a haze of smoke and gases Irom the ^ocorr^^ 
they consist essentially of a system of low-arched, short-span long.tudmal 
sections, just high enough to clear the largest locomotive in use on the 

3H 



f»,C0N>TUlKT10NALl 
Lti ENGlNt.l l<IN(. ~~ J 



KAILWA Y COSSTrwcriON. 



line, with smoke ducts of rrlnloicod • 

gases arc discharged dircc.l^ inf. ,1,,. ^ZT^{r n"""'' "'"'''' "'' '"'-""motive 
l-gh cnc.ui^h to prevent drivin.. rtin o L , """'''' ''"'"'^ ^'^^ '^"i't 

while in addition to these ducts The rool ZlJ^'"" ?''''''"^ '^'^ phnU.n..; 
arc or con,-rct,. .-onstruction. ' '"' ""*' "">' '"'"i"?,^^ '"r Icnces 

COAL AND SAND STATIONS AND ASH-HANDLING PLANTS 
t,o.,l, „hcn stored tn yreat quantities, is subject to 
bustion, uhu-h not only results i„ ,h,. I, ,' , ^ ^' '" spontaneous com- 
thc destruction of the 'bin u hen the l,nTr "'"''' "■"■■"• ''"' "'*" '''""^^ 

steel, and this condition had led to t h t> " '"'"'''"''''''^ «f <--ither wood or 
entirely of reinforced concrete on account JT "n' "' "''''''"''' "^^-P-^d 
possessed by this material, ubik- ,he resnlrs \T ■V"''''"''^^''''"'"^' ''"''"ties 
give entire satisfaction. ""' "'''^""^■'^ ''"^'^ been such as to 




"' '•- Conco!;. coal and'tn : a ^ ^ "" T'"^ '"'' ^^"^ ^'"^'"" - ^'-^ 
'"g, the station consists on ^i '""^'7'^^ '" ^'>- '-■ «enerallv speak- 

'"-^ "f «-". -HI a . fsand" o ; hi'" 'r'^' '^^'"^^ ^ '^^^P-'*-^ °* "^^^ 
-''"d bin. The coal is brought t^tho,:-? I ^™""' "'^' ^" ''''-''^^ '^y 
th''H.gh a ,o-ft. In ,,-rt rack h ^ °" ^ '"'^ ^'■^^'^- ^"^ dumped 

'''livers it into a steel' iucklteleT'".""? ' --P^-^ing feeder, which 

above^or distribution tX-r-'ti""Hf""H'"" ^ '-■""^■^>'°^ ^-"^'^ 
-.ed^,ates and over counter -Sed';;:^:^ r^^ ^iS^^rS 



RAILWAY CONSTRUCTION. 

'": "" -J bvT nd el -a o , .hlch'dumps it fron. abo^c into the dry sand 
;;::' '71 this b " i fed to the eng.nes through two telescopic sand spouts^ 

^■.X2. - ;rrr^rr;.;i:in^:"ti.f:ernrr^s z 

the concrete was ^a^^^ ^^J^a . e' e de^i^ned on the basis of the com- 

'T, 't ■ Tores'sure exerted b the bitun^inous coal weighing 47 lb- P- cu. ft. 

puted lateral P"^"?"^" ""™, ;^,,3„,e of 248 lb. at the bottom of the pocket 

This eave a maximum lateral pressure ui -4 „ , ,^, ft The 




1 -i^ til,, reinforcement consisted of ordinary 
sand and 4 parts broken stone, -^^^/'^^''^, ,..,,,„,es varying from 
round '-S, from^ m. -;^--^ ^^-.X^.^, pi... . great difficulty 
5 m. to .4 "^- centres. In t .^^^^^ ^^^^^.^^ ^^^j^^^j^ ^^.„„,d 

326 



f J, CON.VI tl K"l lONA 1.^ 



RAILWA Y COXSTRUCTION. 



graph (il sinli a plant erected lor the Norfolk ami Western Railway at 
Hluelield. I'he ash bin lias a storaj^c capacity of 30 tons. Aslics are dumped 
from tin- entwine into the i-loTi tubes which rest on trucks in the duni]) pit below, 
witii their tops lliish with the rails, and are raised, dumped into the bin and 
returned automatically by an electric hoist. In the photoj^raph one of thu 
skips is seen in action. The ashes arc emptied from the bin throuj,''h a dis- 
charj^e yate into cars on a track directly beneath. The heig'ht of the bin 
is about 13 It. and the sides are formed of concrete which is only 3} in. for 
the upper 10 ft., spreadinj;' out to <> in. thick ;it the bottom, while the rein- 
forcement emplo\cd is expanded metal and the steel framework supporting the 
l)in is built up ol lolled sleel joists .-uid channels of \arious sizes. 




ROUNDHOUSES AND TURNTABLE PITS. 

Concrete has been extensively used for this work and a sa\ inif has been 
effected in many cases in addition to an improvement in the type of structure 
obtained. In good work the foundations and pits are invariably of concrete, 
and when a good bearing cannot be obtained at a level of a few feet below 
the floor line a great saving can be effected by the use of leinforcement. 
For the construction of the roof there is no material to equal reinforced con- 
crete and the use of steel alone for this work is to be condemned, on account 
of its inferiority as regards durability and fire-resisting qualities, and where 
the roof is constructed of the former material the most satisfactory method 
is to employ the same in the supporting columns. The columns on the inner 

327 



RAILWAY CONSTRUCTION. 



[CQNCRET EJ 



circle, to which the doors are attached, can with advantag'e be of steel or cast 
iron in preference to concrete. In the case of a structure roofed with rein- 
forced concrete the outer walls may be ol lirick, plain concrete, reinforced 
concrete, or plaster. 

Concrete will give good results under nearly all conditions, while plaster 
walls may be employed when it is required to reduce the initial outlay to a 
minimum. These walls are constructed of expanded metal covered with Port- 
land cement mixed with sufFicieni limi- to allow it to be worked with a trowel. 
The former is stiffened with rods and channel irons, which are used to support 
the window frames. A wall of this character can be built more quickly 
than a concrete wall, is efficient and should be durable. If damaged by a 
locomotive, or otherwise, it is easily repaired and alterations can be readily 




made. \\ lien used with concrete columns it should not crack and its first cost 
is only about one-half that of a brick wall. 

Reinforced concrete is particularly economical in the case of large round- 
houses, when the forms for each unit or stall can be used many times. A 
good example of this t\pe of structure is the VVaterbury roundhouse, which 
appears in Fig. 14, which is designed to include 22 stalls, although at the 
present time only one portion, comprising 10 stalls, has been erected. Each 
stall comprises about 8 degrees of the circle and one end of the building is con- 
nected to a machine shop. The house consists of four circumferential rows of 
hooped concrete columns carrying beams and roof slabs of reinforced concrete, 
while the outer circle is enclosed by a brick wall with large glass windows with 
concrete sills directly in line with the tracks. The columns, which are over 

328 



r|J,CX>N.<i1BUC-nONAl.l 
L&.EN(jlNt.r-WIN'' ~J 



RAIIAVA y CONSTRUCTION. 



20 It. in luiL;lil, ::rc ol stiuarr MCtioii, 14 In. by i .) in., and .-irr rrinloiicd wilh 
six l; in. pl.iin squ.nc bars hooped with ;; In. round hoopins^ \ in. pitcli. 

Ill loinii liion with loiindiiousc construction, the siil)jcct of turn-table pits 
is of ispicla! intrrcsi, and practically al! these are now constructed of concrete. 
The linn-lahle is usually supported by a centre pier surmoiniled bv a com- 
plete templali- about 5 It. sq. by iS in. lliick. 'llie concrete lor the pier 
ilsell may be mixed in the proportion ol 1 part Portland cement to ^ parts 
sand and h parts broken stone, and lor the tem|)late in the proportion of 
1:1:-'. The llooi' ol the pit usually consists of about 4 in. concrete (1 : J : 4) 
iaitl on S in. of well tamped cinders, wliile thi' circular tail is carried on a 
scat of I : 3 : h concrete, restinj^ on a foundation 5 ft. wide bv 4 ft. liii^h. 

SIGNAL TOWERS. 

The temporary structures used for this class of buildini^ ,ire being 
superseded almost without exception by concrete buildinifs of a permanent 
nature, uhicli in many cases have been desitrned on verv artistic lines. The 
signal to«(r illuslrated in F/V. 15 is a typical example, and with the exception 
of the loof, which is of tile on wooden rafters, it is of concrete construction 
throughout. The foundation and both exterior and interior walLs are of 




plain 1:3:5 gravel concrete, while the floors are of 1 
reinforced with No. 16 2i-in. expanded metal. 



: 4 gravel concrete, 
329 



RAILWAY CONSTRUCTION. 



ICDNCBETFJ 



WATER TANK SUPPORTS. 

Ri-iiiforced concrete has been much used in the construction of water 
tank supports and its strength, rig^idity and resistance to fire and decay render 
it very suitable lor this class of work. A g-ood example is that of the water 
tank support at Waterbury, N.Y.N.H. and H. Rly., illustrated in Fig. i6, 
which is octagonal in form and 30 ft. 9 in. wide, with the platform carrying a 
55,4QO-gallon wooden tank 40 ft. above the ground line. The method of rein- 
forcing the supporting columns presents a rather unique and interesting feature, 
consisting as it does of two 95-11}. third rails placed back to back and riveted 
every 3 ft., making a section in the form of a star strut. The platform, which 
is 9 in. thick, is reinforced with ^-in. corrugated bars at 4-in. centres in both 
directions, while the beams and diagonal braces are reinforced with g-in. 
corrugated bars, bent and hooked as necessary. Concrete for the support was 
mixed in the proportions of i part Portland cement to 2 parts sand and 4 parts 
screened gravel. 




BUMPING POSTS. 

.'V Ijumping post, to ensure safety against rotating or breaking down 
under constant buffing, must be constructed so as to be anchored in the earth 
direct rather than be attached to the track itself. By the use of concrete, 
bumping posts can be constructed economically so as to meet the conditions 
of stability and permanence. 

POWER STATIONS, 

The construction of a large number of power stations has become neces- 
sary during recent years, owing to the electrification of many railway systems, 
and concrete has been extensively adopted on account of its fire-resisting 
character, resistance to vibration and freedom from deterioration. The power- 
house illustrated in Fig. 17 is located at Cos-Cob on the .Miames Ri\er, about 
one mile from Long Island Sound. The interior is divided into a turbine-room 
60 ft. wide by 112 ft. long, with a switch board occupying an additional 

330 



rf, CCNyreUCTlONA t] 



RAILWA Y COS'STrWCTION. 



space of 25 It. by 1 id ft. and a boiler-room 160 ft. long by no ft. wide. 
'J'he foundations, coliirnri fo()tin£j.s and walls up to the water-table are mono- 
lltiric roncritt' mixed in the proportions of i part Portland cement, 3 parts 
.sand and 5 parts 2-in. crusbcd f^'ranite. l'"or the water-table, window arches, 
copinij and window-sills inoncililliir 1)locks are used made of concrete composed 
of the same proportions as tin- ollur monolithic work. The walls above the 
water-table are of hollow blocks 10 in. by ij in. by 24 in., composed of a mix- 
lure of I part cinicnl, ^ parts sand and ; parts 1 [-in. crushed jjranite, faced on 
the exterior surface with a mixture ol 1 of cement to 2 of sand, and where 
ihe inner surlaci' of llie wall is exposeil, with a mixture of i part cement to 
4 parts sand. All the window lintels were cast in position and consist of 
1:3:5 concrete reinforced with two J-in. trussed bars. In desit^ninf^ the 
structural features of the buildinsj, the followin<| live loads per sq. ft. were 
used : Coal bin lloor, 550 lb. ; engine-room and jjallerv floors, 400 lb. ; boiler- 
room floor, 340 lb. ; fan-room floor, 200 lb. ; and roof, 30 lb. The columns in 




the boiler-room .iix ul stnulm.il stci 1, but .ill uilu 1 i.ihimii-, in the buildins^ 
are composed of concrete blocks made by fillins^ the cored air spaces of the 
hollow blocks with concrete of the same mixture as the blocks themselves. 
Over the turbine-room, where there arc no steel columns, the steel roof 
trusses arc carried by the concrete block wall, the blocks being solid for several 
courses below the trusses to properly distribute the load, and over the boiler- 
room the trusses are supported by the walls and the interior steel columns. 

SHOPS AND WAREHOUSES. 

The same advantages which reinforced concrete possesses over other 
materials lor the construction of power-houses arc equally enjoyed by it 

331 



RAILWAY COXSTRL'CTION. 



iCQNCBFTFJ 



as a material for shops and warehouse building's for rail\va\ purptises, and 
an example is shown in Fis;. i8, which is a photograph ol the- Mott Ha\en 
car shops, X.V.C. and H.R. Rly. These shops are 2^0 fl. long, 45 ft. 10 in. 
wide, and, as will be seen from the illustration, thev are built in alternate high 
and low- bays, the former 25 ft. high and the latter 19 ft. 4 in. .\s windows 
are provided in each side of the high bays above the roof of the low ones 
this construction takes the place of the ordinary saw-tooth roof. In general, 
the buildings consist of 2^-in. cement mortar curtain-walls reinforced with 
truss metal lath, No. 28 gauge, resting on a concrete foundation wall rising 
4 ft. abo\ e the ground level. The roof is can led on light-angle trusses 
supported by 1 beam columns placed every ih ft. 8 in. at the division between 
the adjoining high and low sections. Between the columns and window frames 
steel girts are placed to form a support lor the truss metal lath reinforcement 




of the walls. The metal lath was kept in position and held rigidly by means of 
temporary i-in. by i-in. angles spaced about 2 ft. apart. The mortar, which 
was mixed in the proportion of i part Portland cement to 3 parts sand, was 
applied in the same manner as plaster for an ordinar\- wall. 

GRAIN ELEVATORS. 

The ideal grain elevator must possess the all-important and essential 
qualities of being absolutely proof against fire, water or dampness, dust and 
vermin, and for this reason reinforced concrete is especially adapted. These 
elevators may be grouped into two classes, according to the arrangement of 
the bins and elevating machinery — viz., elevators which are self-contained, 
with all the storage bins in the main elevator or working house, and elevators 
consisting of a working house which contains the elevating machinery and 
storage bins connected with the working house bv convevors. Reinforced 



RAIIAVA y COXSTRrCTION. 



concrete elevators are commonly Ijuilt of the latter type with a w orkins,' house 
that is g-encrally rectang'iilar in shape, with either square or circLilar bins con- 
nected with the inckpendent storage bins, which are usually circular. The 
photot;ra])h in Fiu^. 19 illustrates a jj^rain elevator being constructed. In 
elevators of this type the storage bins arc reinforced both horizontally and 
vertically. The horizontal reinforcement is either single when it is placed 
in the centre of the wall or double when the bars arc placed near the surface. 
This reinforcement may be continuous, rising from the bottom to the top 
as a spiral, in which case high steel is generally used, or it may be placed in 
separate rings. The vertical reinforcing bars arc equally spaced and are wired 
or clamped to the horizontal rods, at intersections. The horizontal reinforce- 
ment is generally designed to take all the tensile stresses resulting from the 
pressure of the grain while the vertical reinforcement carries the load between 
llie horizontal reinforcement and lakes its proportion of the vertical load. 
The walls haxc a negative bending moment at the points of horizontal rein- 
forcement and a positive bending moment half way between the horizontal 
reinforcement. The pressure on any horizontal section equals the weight of 
the wall plus the weight of the grain carried by the walls, and this pressure 
is carried I)\' both the concrete and the steel. 

STORAGE RESERVOIRS. 
The advent of power plants into the sphere of railroad engineering renders 
it necessary to construct storage reservoirs to supply these plants with water, 
and here, again, has reinforced concrete been extensively adopted. These 
reservoirs are most economically built of circular form and all the tensile 
stresses must be taken by the steel hoops. In buildipg water tanks the 
materials for the concrete must be very carefully proportioned in order to 
give a watertight wall, and the stone must be of such size that a good surface 
can be easily obtained. The proportions used to resist percolation of water 
usually range from i : i : j to i : 2i : 4^, the most common mixture being 
1:2:4. The concrete should be mixed so jhat it will entirely cover the 
reinforcing metal and flow against the form, and it is absolutely' essential 
that the concreting for the entire tank should be done in one operation, or 
else that the surface be specially prepared and treated to make watertight 
joints. 

DOCKS. 

Inasmuch as practically every railroad system owns valuable water front 
the question of dock construction is an important one. In the tropics, where 
tlic waters are infested with limnoria and teredos, which destroy a wooden 
pile in a few years, and where the very atmosphere itself eats away unpro- 
tected wooden and steel structures, reinforced concrete is especially adapted 
to the construction of wharves and warehouses. Practically all the docks of any 
magnitude now being constructed in South and Central America and the 
Philippines are designed as entire concrete structures. The Almirante wharf 
of the Changninola Railway at Bocas del Toro, Panama, illustrated in Fig. 20, 
is an interesting example of this tvpe of construction. It is approximately' 
700 ft. long and 54 it. wide and is connected to the mainland by a crcosoted 
limber trestle approach about 800 ft. in length. .\s the purpose for the wharf 

333 



RAILWAY CONSTRUCTION. 



ICDNCBETFJ 



is the loading- of bananas on to thu outsjoing and the temporary stora"-e of 
general merchandise received from the incoming steamers, the front of the 
wharf for a distance of 2;^ ft. is open lo allow the free use of automatic loading 
machines, while the remainder is coxered with a steel storage shed open 6 ft. 
from the bottom in the rear and 14 ft. in the front. The wharf consists of a 
series of reinforced concrete columns supporting a system of main girders and 
cross beams, which in turn carry a 7-in. floor slab. The columns rest on 
wooden piles spaced at 10 ft. centres, protected by a 4-in. covering of con- 
crete. This method of protecting the wooden piles from the attacks of teredos 
consisted in driving a j-in. concrete shell — 20 in. in diameter at the top and 




HA75 



16 in. at the bottom, reinforced its full length with 4 in. by 12 in. wire cloth — 
over the wooden pile and into the harbour bottom 2 ft. The shell was then 
sealed at the bottom with concrete, the water pumped out, and the intermediate 
space betw een the shell and the pile filled with concrete to the level of the top of 
the shell, which was about 2 ft. above the top of the pile and i ft. above high 
water. The shells were made in lengths varying from 32 ft. to 12 ft., accord- 
ing to the depth of water, and were composed of concrete mixed in the propor- 
tions of I part Portland cement to 2 parts of crusher dust to 3 parts of i-in. 
broken stone, and the filling consisted of concrete mixed in the proportions of 
1:2:4. 

In constructing the columns, girders and beams a mixture of i of cement, 
2 of sand and 2 crusher dust to 3 of i-in. broken stone was used and for the 
floor slabs a mixture of 1:2:1:3 o' the same materials. The reinforcing 
rods for the columns were embedded 4 ft. in the filling between the shells 

3.H 



fTTcc 



RAILWA Y CONSTRUCTION. 



and the piles and were carried up throuj^h tiie main g-irders and into the floor 
slabs, thus securely tying- together the entire structure. For the columns, main 
girders and railway beams ;-in. rounti rods were used for reinforcing and for 
the lloor slaljs A-in. round rods. 

TUNNELS. 

One of the most important uses of both plain ami reinforced concrete is 
in the construction of tumuls, and the expensive and dangerous maintenance 
work which is necessary willi hrlck-lined tunnels is practicalh- eliminated hv 
the use of concrete. 

Fig. 21 shows the Hcrgc n I till tumul, which is /^o ft. wide in the clear and 
2^ ft. 5 in. high from the l)ase of the rail to the crown of the roof arch, 
with a concrete lining of a minimum thickness of 2 ft. The length is 4,280 ft. 




and it is connected to tlie old tunnel, which is immediately alongside at two 
points. The comparison between these two tunnels in the question of main- 
tenance has shown a very great advantage in the use of concrete. 

RAILWAY SLEEPERS. 

One of the most serious and perplexing questions which confront tile 
railway engineer is the problem of dealing with railway sleepers. As evidence 
of this, during one year the railways of the United States of .\merica use, 
apprv)ximalel\', 118,000,000 sleepers, a verv large percentage of which are 
renewals. This means a great strain on the rapidly decreasing supply of 
timber, which is becoming high in price and not always good in quality, with 
the result that a substitute is required, and this fact has led to experiments with 
concrete sleepers of different types. While none of these have been tested 
long enough under heavy and high-speed trafTic to warrant selection as a proper 

3 3 5 



RAILWAY CONSTRUCTION. ICDNCRETEl 

substitute for w oock-n sleepers under all conditions, the success of some of the 
sleepers tested has been great enouifh to convince railway engineers who have 
given the most study to the subject that a properly reinforced concrete sleeper 
with proper fastenings is a practical and economical one, at least for tracks 
where the speed is low and where conditions are adverse to the life ot wood or 
metal. There is no question that concrete sleepers are eminently suitable 
and economical for use in vards and sidings, and that there is an enormous 
place for their introduction into this field alone. Illustrations of reinforced 
concrete sleepers have appeared on many occasions in our columns, and we 
need not reproduce these in this article. 

TELEGRAPH POLES. 

\\"e have on more than one occasion dealt with the advantages of reinforced 
concrete for telegraph poles, and there is no doubt that this material is specially 
adapted to work of this kind. They have been extensively used in the United 
States, Germanv, Denmark, and Switzerland, and we hope that we shall not 
be slow to follow, as their application would mean a considerable saving in 
expense and their reliability and low maintenance charges should certainly 
commend themselves to the authorities concerned. 



336 



STANDARD BUILDING RHCU LATIONS 



^^Fi STANDARD BUILDING REGULA^ 

iST- If TIONS FOR THE USE OF ,^ §Mli 

;Pm<:i£^-'^ REINFORCED .-JO^*^^-^ 

.ji^>^t!S^v CONCRETE. 'VK 0^"^!^ 
JS^^TlS?^ . ^,.^'>*%^ 




Wt- thuiti .1 Lt'rv ('/ ('If .tffiL-riJeJ building regatjfions proposed jt the recent Coni'cnuon 
of the National Association of Cement-users of Atnertca should be very interesting at this 
stage, and tve are therefore presenting it in full, — ED, 



Till- follow iiii; is the aniciuied code which was Noted on at the Convention of 
tlie National Association of Cement L sers held in Chic.igo in Pebruarv last, 
and which has been sent out for letter ballot. 

I. The term " Reinforced Concrete " shall he undcrstoixi to mean an approved 
concrete which has been reinforced by metal in some form so as to develop the com- 
press-ive strength of the concrete. 

CLASS OF BUILDINGS. 

J. Reinforced concrete may he us<'d for all classes of buildings if the design is in 
acccrdance with good engineering [>ractice and stresses are figured as indicated in these 
regulations. 

HEIGHT. 

3. There sliall be no limit u|>on the height of buildings of reinforced concrete except 
as limiti".! by the requirenienls in these regulations. 

PLANS. 

4. Before permission is granted by the Building Department to erect any reinforced 
concrete building, complete plans, accompanied by specifications, signed by the 
engineer and architect, must be filed with the Building Department and remain on 
file for public inspection imtil the building is completed. 

5 The Building Department shall b.ive access to the computations, which shall 
give the loads assumed separately, such ,is de.id and live loads, wind ,ind impact, if 
any, and the resulting stresses. 

SPECIFICATIONS. 

6. The specifications sh.all state the cjualities of the materials to be usi'd for making 
the concrete, and the proportions in which they .are to be mixed. 

7. Upon the completion of the building the engineer and architect shall issue, 
under the approval of the I?uilding Department, signed certificates, to lie posted on 
each lloor of the building, stating the safe carrying^ capacity (X?r square foot. 

RECORDS. 

8. There shall be kept an exact record of the progress of each operation where 
the same can be inspected bv the I^uilding Department. These records shall show 
the date of placing of all the concrete and date of removal of the forms, and must 
be turned over to the Building Department when the building is completed. 

WALLS. 

q. Reinforced concrete walls mav be used in place of brick or stone walls with 
thickness reduced two-thirds the thickness called for, for brick walls. Curtain walls 
shall be not less than 4 in. thick. 

10. Concrete walls must be reinforced in both directions. The maximum spacing 
of reinforcing bars shall be 18 in. between centres, reinforcement in both faces of the 
wall being considered. Total reinforcement shall be not less than one-fourth of i per 
cent. 

3.^7 



REINFORCED CONCRETE. [CQNCKEJE] 

TILE AND JOIST CONSTRUCTION. 

11. Wherever floor constructions are built with a combination of tile or other fillers 
between joists, the following ru'es regarding the dimensions and methods of calcula- 
tions of construction shall be observed, (a) Ratio of minimum depth to clear span of 
joist shall be not greater than one to eighteen, (b) Wherever a portion of the slab 
above the tile-joist shall be considered as acting as a T-beam section, the slab portion 
must be cast monolithic with the joist, and must have a minimum thickness of at least 
2 in. on all spans. Otherwise all regulations applying to T-beams shall apply to tile 
and joist construction, (c) Where the joists are figured as rectangular beams, in 
accordance with the standard regulations for this type of beams, the slab shall be 
considered as independent of the structural part of the building, (d) Wherever porous 
tiles or other materials which by their nature will absorb water from the concrete, are 
used between the joists, care must be taken thoroughly to saturate the tiles, or other 
materials, with water immediately before the concrete is placed, (c) Reinforcement 
for slabs over joist construction below 30-in. centres need not be closer than 24 in. 
in each direction. 

CEMENT. 

12. Only Portland cement shall be used in reinforced concrete structures. Portland 
cement shall meet the requirements of the Standard S-j^ecifications for Cement of the 
.American .Society for Testing Materials. (See Standard No. i of the National Asso- 
ciation of Cement Users.) 

13. Tests of cement used in building operations sli.ill be made from time to time 
under the supervision of the Building' Department in accordance with the preceding 
s[:)ecifications. No brand of cement whicli has not met tliese requirements shall be 
used. 

AGGREGATES. 

14. Extreme care shall be exercised in selecting the aggregate for mortar and 
concrete, and careful tests must be made, where any doubt exists, of the materials for 
the purpose of determining their qualities and the grading necessary to secure maximum 
density or a minimum percentage of voids. 

15. Fine aggregates shall consist of sand, crushed stone or gravel screenings, 
passing when drv a screen having \-\n. diameter holes, and more than 6 per cent, 
passing a sieve having 100 meshes jier lineal inch. It sh.dl be clean, silicious material 
free from vegetable loam or other deleterious matter. 

16. Mortars composed of one part Portland cement and three parts fine aggregate 
by weight when made into briquets should show a tensi'e strength of at least 70 per 
cent, of the strength of 1:3 mortar of the same consistency made with the same 
cement and standard Ottawa sand. 

17. Coarse aggregate shall consist of inert m.aterial, such as crushed stone or 
gravel, which is retained on a screen having J-in. diameter holes; the particles shall 
h>e clean, hard, durable, and free from all deleterious material. The maximum size 
of the coarse aggregate shall be such that it will not separate from the mortar 
in laving, and will not prevent the concrete fully surrounding the reinforcement or 
filling all parts of the forms. 

18. The maximum si/e for reinforced concrete shall be such that all the aggregate 
shall pass a ij-in. diameter ring. 

CINDER CONCRETE. 

iq. Cinder concrete shall not be used for reinforced concrete structures; it may 
be used for fireproofing. \\'here cinders are used as the coarse aggregate they shall 
be composed of hard, clean, vitreous clinker, free from sulphides, unburned coal or 
ashes. 

REINFORCE ^'ENT. 

20. Medium steel for reinforcement of concrete shall be made from new billets, 
and shall conform to the requirements of the specifications for structural steel adopted 
bv the American Railway Engineering and Maintenance of Way Association. The 
Building Department shall at its option in lieu of this grade of steel accept medium 
steel meeting the requirements of the manufacturers' standard specifications, provided 
the Building Department shall be furnished with the results of two tests made originally 
by the manufacturer — tests being taken from each melt, one for bending and cne for 
tension; and provided further that the contractor furnishing such steel shall furnish 
such additional bars of all sizes for thoroughly testing by the Building Department. 

338 



^jaEI 



STANDARD liUILDlNG REGULATIONS. 



ji. llifih L-lastic limit steel shall have (i) an elastic limit of ^u.ouo lb. to O^.txH) lb. 
per square inch, (2) a minimum elonication in [3er cent, in S in. of 1, 000, 000 -h (ultimate 
strenfjth), and (i) be capable of cold bendinij 180 dej^. around four diameters without 
fracture. 

MIXING. 

jj. The inf,'redients of concrete shall be thoroujfhly mixed to the desired consistency, 
;uk1 the mixinf,' shall continue until the cement is uniformly distributed ;ind the mass 
i, uniform in colour ■,\n<!i homoi^eneous. 

23. Methods of measurement of the pro|X)rtions of the various int,'redients, includ- 
ing the water, shall be used, which will secure separate uniform measurements at all 
times. 

24. Machine-Mixing. — When the conditions will ix-rmit, .1 machine-mixer of a 
tvpe u liich insures the proper mixing of the materials throuf^hou. the ni.ass shall be 
used. 

25. Hand-Mixing. — When it is necessary to mix by hand, the mixinjif shall be 
on ,1 w,iter-lii;lil plailorm, and especial precautions must be taken to turn the materials 
until tiK'v ,ire homogeneous in appearance and colour. 

26. Consistency. — The materials must be mixed wet enouf^h to pr<Kluce a concrete 
of such a consistency as will How into the forms and about the metal reinforcement, 
,nul which, on the other h.md, can be conveyed from the mixer to the forms without 
se|),ir,ition of the coarse a{,'}^rei;'ate from the mort.'ir. 

27. Retem|X'rin4j mort.ir or concrete, i.e.. re-mixin;.; with w.-iter after it has parth 
set, shall not be pcrmilted. 

PLACING CONCRETE. 

28. (.'oncrete shall be placed in the worlc immediately .after niixinj;, ;md de|X)sited 
and rammed or afjitated by suit;ible tools in such a manner as to pnxluce thoroufjhlv 
compact concrete of maxiimim density. No concrete shall be placed until the rein- 
forcement has been pl.iced .and firmly secured by wirinj.^ or other methods to prevent 
dis|)lacement. 

2c). The faces of concrete exposed to premature drying shall be kept damp for a 
period of at least seven d.ays. 

30. Before pl.icinjj;^ the concrete care shall be t.iUen to see that the forms are 
substantial and thorouji^hly wetted and the sp;ice to be occupied, by the concrete free 
from debris. When the i)lacins^ of the concrete is suspended, all necessarv ijroovcs 
for joining- futun- \\H)rk shall be made before the concrete has had time to set. 

31. When work is resumed, concrete previously placed shall be rouejhened. 
thoroughly cleansed of foreign material and laitance, drenched and slushed with a 
mortar conivisling of one part Portland cement and not more than two parts fine 
aggregate. 

32. Placing in Water. — Concrete should not be'i)laci'<l in water, unless unavoid- 
able. Where concrete must be placed under water unusual care must be taken to 
pn'xent {\w cement from being floated away. 

33. Freezing Wea/Aer. -Concrete shall not be mixed or deposited at a freezing 
ttniper.ilure unless speci.il |)recautions are t.aken to avoid the use of materials contain- 
ini,' frost or covered with ice crystals, and to provide means to prevent the concrete 
from freezing after being placed in position and until it has thoroughlv hardened. 

PLACING REINFORCEMENT. 

34. The reinforeemenl shall be .iccurately loc-itcd in tin- foriiis anil secured against 
displacemenl. 

JOINTS. 
35. Reinforcement. — Wherever il is necessarv to splice reinforcement bv means 
of lapping, the length of the la]) shall be determined upon the basis of the safe bond 
stress and the stress in the bar at the point of splice; or a connection shall be made 
between the bars of sufficient strength to carry the stress. Splices at the point of 
maximum stress must be .avoided. 

36. In columns large bars (bars with area equal to ij in. diameter round or 
larsjer) shall be properly butted and spliced. .Smaller bars may be lapped as indicated in 
paragra|)h 35. 

37. Concrete. — Reinforced concrete work shall be stopped at such points tliat the 
'oints will have the least possible etTect on the strength of the structure. Footinq-s 

s .'39 



REINFORCED CONCRETE. 

shall be cast to their full depth at one oi)eration. (a) Columns. — Work in columns shall 
be stopi>2d at the underside of the lowest projection at the head of the column, (fc) 
Beams and Girders.— Construction joints in beams and j,Mrders shall be vertical and 
within the middle third of the span. Any concrete which may nm past the bulkheads 
must be cleared up before the concretini,' of the ne.xt section is started. Where brackets 

;'re used, the brackets shall be considered as a part of the beam or girder, (c) Slabs. 

Construction joints in slabs shall be near tlie centre of the span. No joint will be 
allowed between slab and beam or girder. 

REMOVAL OF FORMS. 

38. L'nder no consideration shall forms be removed until the concrete has hardened 
sufficiently to |>ermit their removal with safetv. 

39. Floor Slabs and Beams. —Forms shall not be removed from floor slabs in 
less than seven days. .Sides of be.ims may be removed at the same time as the floor 
slabs, provided original supports under be:uns and girders are left in place. 

40. Columns. — Where original supports remain under beams and girders coming 
to the columns, the forms shall not be removed from the columns in less than four days. 

REMOVAL OF SUPPORTS. 

41. Beam and Girder Supports. — The original supports for all beams and girders 
must remain in place at least ten days, but all beams and girders having more than 
30 ft. span from centre to centre of support shall be considered as special cases and 
shall be subject to inspection of the Building Department before removal of supports. 
The length of time before the removal of forms shall be increased in all cases and 
additional time for each and every day that the thermometer registers an)- time during 
the day or night below 35° Fahrenheit. 

ASSUMPTIONS IN DESIGN. 
42. Internal Stresses. — .As a basis for calculations for the strength of reinforced 
concrete construction, the following assumptions shall be made: (a) .-\ plane section 
before bending remains plane after bending, (b) The modulus of elasticity of concrete 
in compression within the usual limits of working stresses is constant, (c) In calculat- 
mg the moment of resistance of beams the tensile stresses in the concrete shall be 
neglected, (d) Perfect adhesion is assumed between concrete and reinforcement. Under 
compressive stresses the two materials are therefore stressed in proportion to their 
moduli of elasticity and their distance from the neutral axis, (e) The ratio of the 
modulus of elasticity of steel to the modulus of elasticity of concrete shall be assumed 
to be 15. (/) No allowance shall be made for tension in concrete, (g) Initial stress in 
the reinforcement due to contraction or expansion in the concrete may be neglected. 
ill) In columns tlie ratio of le.'ist diameter to height shall be taken as one-fifteenth, 
(ire.ater ratios shall be deducted bv s.itisfactory column formute. 

43. Length of Beams and Slabs. — The si>an length for beams and slabs shall be 
taken as the distance from centre to centre of supports, but shall not be taken to exceed 
the clear span plus the depth of beam or slab. Brackets shall not be considered as 
reducing the clear span. 

44. Length of columns shall be taken as the maximum unsupported length. 

45. Where slabs and beams are figured as simple beams the length shall be con- 
sidered as the clear distance between supports excluding brackets. 

LOADS. 

shall include the weight of the structure arid all fixed loads and 

^ht of the reinforced concrete shall be taken as 150 lb. per cu. ft. 
load shall include all loads and forces which are variable. The 
minimum live load fi>r tloi>rs and roofs shall be as generally |)rovided by building codes. 

49. Roof and Floor Loads. — The roof shall be figured to carry 30 lb. live load per 
square foot unless otherwise noted. 

30. -A reduction of live load coming to the column supjjorting the floor below the 
roof of 5 per cent, to be allowed and a further reduction of 5 per cent, of the live load 
of each ston,- below until the total reduction shall amount to 50 per cent, of the live 
load of anv floor, after which all loads shall be figured net to the foundations. These 
reductions shall not apply to storage warehouses. 

340 



46. 


The dead 


forces. 




47- 


The weig' 


4''^- 


The live 



lA-SoiNgu?.;?^'^] STAM)ARn liUILDIXG REGCLATIONS. 

SI deduction of Loads. Su rwiucliun of loads sliall be- allowed for tk'urin" 

floor slal)s. '^ -"^ 

5J. No reduction of loads shall be allowed for fitfiirijij,' beams 
5J. A reduction of ,5 ,xM- cent, live load may be .allowed in liKurinf,' the girders, 

except in biiddnif^s used for storaj,'-e inirposes. 

54. 1.1 assuinin- the load coming' to the columns all fx-.uns and i^irders shall be 
considered as carrymf; a net load consislin>,r of ,00 ix-r c.-nt. ,ach of live and dead load, 
subject to the above rixluctions. 

BENDING MOMENTS. 

55. Slabs.~The bending,- moment of slabs uniformlv lo.aded .and supported at two 
sides only sh.all b<' taken as ;e/-',/S, where ;.■ _ unit load and / = span 

56. Contlauous Slabs.~\-vr fnterior slabs overhatiginR two or more supports the 
benduiK nu.m.nt shall Ih- t.aUen as -.W--, 12. The reinf<,rcement at the top of the slab 
over supports niusl eipial th.al used at the centre. 

57. Slabs Reinforced In Both Dlrectlons.-Shxbs that are reinforced in both 
directions and su,;porled on b.tir si<les .and fully reinforced over the supports (the 
reinforcement passing mlo the .adjoining slabs) m.ay be llgured on the basis of beiidin- 
moments equivalent to -^vU 1 b for lo.ad in e.ach direction. When span under consider.-T- 
tion is not continuous, /—S; when continuous over one sup|>,>rl, /••=io- when con 
linuous over both supports, /■ = ,2. The distribution of the loads to be dc'terinin.d bv 
the formula: r=U^(L. + U), in which r equals proportion of load carried bv the 
transverse reinforcement, /, equals length of span, ..nd b equals breadth of slab ' 

5.S. Ihe sl.ib are;, m.ay be reduced by one-half, as above ligured. when the rein- 
forcement is p.-,r.a!lel to and not farther from the sup,x>rts than one-quarter of the 
shortest side. Ihe reinforcement si>.anning the shortest direction shall be below the 
reinforcement spanning the longer <lirection, and shall not be further apart than two 
and a half limes the thickness of Ihe lkx)r, including the linish. 

59. Simple Seams- The bending moment of beams supported at the ends onlv 
snaii oe lii^urr-tl as ot sunplr Ih-mmis. 

60. Partially Restrained Beams.~n,.u^^^ sup,>orted at .me end and continuous at 
tie other to he hgured p.utially restr.ained with a bending moment of eight-tenths that 
of a simple he.am W hen the over-all vertical distance of the tension members is greater 
than one-sixth ot the total depth of the bean, the stresses in e.ach >fieml>er shall tx- co-r- 
puted in proix>rtion to the distance from the neutr.al axis. 

Tm. Be.ams supporting rectangular slabs reinforced in both <lireclions shall be 
.assumed to take the following load : The be.anis on which the shortest sides of the sl.ab 
rest shall take the lo.ad of that portion of the slab formed bv the isosceles triangle havin- 
this side as Its base .and h.alf this side .as its height, the load from the remaining 
,)ort,on of the slab shall go to the beams on which the long side of the slab rests ^ 

62 Continuous Beams.-WWn be.ims or girders are continuous over two or nore 
supports, the uu.ru.i beams may be considered as partiallv restrained, and the bendino- 
moments at the centre and support ligured as two-thirds that of .a simple beam, unles^ 
the concrete at the bottom of the beam at the support shall bv this consideration revive 
excess compression. 

63. T-Beams. -In be.am and slab construction, an effective metallic bond should be 
Tn'r:; ';'/'"i/^'"^-!'7' -' 'h- "^--^ «"^' f'-'-b- VVhen the principal slab reinforcement 
girSer'Swdlintcflll^fsiar""""^ reinforcement shall he u.-d extending over the 

64. \\-here adequate bond between slab and ueb of beam is provided, the slab mav 
be considered as an integral part of the be..am, but its effective width shall not exceed 
one-sixth of the span length of the beam on either side of th<. Ix-am. nor be grea er than 
ecU,4'Tthe w-eb. '"''' "" '"'"'' "" ''"'^' ''''" "^ '^^ '"''>■"• •^'-^'^"''ements from the 

be X%nll'l\^ '^^^'^'' ofT-beams acting- as continuous beams, due consideration should 
^ guen to the compressive stresses at the support at the bottom of the beam. 

WORKING STRESSES. 

mivff- ^^°"'-"''«e composed of materials meeting the requirements of these regulations 
shall dl" P^^l^'-''"" '^^ °"« P^--' "f cement and six parts\f ag.gregate (fine and coarse' 
shall develop a compressive strength of 2,000 lb. per sq. in. in 2.S davs when tested as 
8-in. diameter cylinders ,6 in. long under laboratory conditions of manufacture and 

E 2 



REINFORCED CONCRETE. [CQNCBETE] 

storage, using the same consistency as is used in tiie field. When the i-iropoinion of 
cement is increased, using the best quahty of aggregates, an increase may be made in 
all working stresses proportional to the increase in compressive strength at 28 davs, as 
determined by actual tests, but this increase shall not exceed 25 |X'r cent. On this basis 
the following working stresses shall be allowed in construction ; — 

67. Bearing compression, 650 lb. [ler sq. in. 

68. Compression in extreme fibre, (150 11). ]icr sq. in. ; witli increase of 15 per cent, 
near supports in continuous beams. 

69. .Axial compression in columns wilhoui hoops, ^50 lb. ])er sq. in. and 6,750 lb. ]>er 
sq. in. on vertical reinforcement. 

70. .Axial compression in columns with i per cent, of hooping, 540 lb. per sq. in., 
and 6,750 lb. per sq. in. on vertical reinforcement. 

71. .\xial compression in columns with i per cent, hooping and 1 to 4 j>er cent, of 
vertical reinforcement, 650 lb. per sq. in. on the concrete and 9,750 lb. on the vertical 
reinforcement. Where it becomes necessary or desirable to use vertical reinforcement 
of size equal to or larger than a section ij in. round bar, the ends of all longitudinal 
reinforcing members must be finished to a plain bearing surface and provision shall be 
made for properly-holding reinforcing members in line, and while the concrete is being 
deposited. The bars in the base of such columns shall bear on a plate or casting, or 
shall be enlarged so as to reduce the bearing stress at the bottom to the stress given in 
paragraph 67. In lieu of plate an enlargement for bearing the stress may be distributed 
to the footing by means of dowels with planed upper ends, length of the dowels being 
sufficient to distribute the stress by means of the bond of the dowel. In the footing 
the concrete bond stress to be as given in paragraph 74. The footings supporting 
columns where hooping and vertical reinforcement is used shall be enlarged to at least 
six inches on each side of the column, ineasurements being taken from the centre of the 
hfwping. Bars composing longitudinal reinforcement shall be straight and shall have 
sufficient lateral support to be securely held in place until the concrete is set. The clear 
spacing of bands or hoops shall not be greater than one-fourth the diameter of the 
enclosed column. .Adequate means must be provided to hold bands or hoops in place so 
as to form a column, the core of which shall be straight and well centred. Bending 
stresses due to eccentric loads must be provided for by increasing the section until the 
maximum stress does not exceed the values above specified. 

72. Compression on columns reinforced with structural steel units which thoroughly 
encase the concrete core, 540 lb. per sq. in. on tlie concrete and 8,100 lb. ])er sq. in. on 
the structural steel. 

73. Web Stresses. — In cilculating web reinforcement the concrete sliall be con- 
sidered to carrv 40 lb. per sq. in., the remainder to be provided for by means of reinforce- 
ment in tension. Members of web reinforcement shall be embedded in the compression 
portion of the beam, so that adequate bond strength is provided to develop fully the 
assumed strength of all shear reinforcement. They shall not be spaced to exceed three- 
fourths of the depth of the beam in that portion where the shearing stresses exceed the 
allowable shearing value of the concrete. \\'eb reinforcement, unless rigidly attached, 
shall be placed at right angles to the axis of the beam and looped around the extreme 
tension member. 

74. Bond between plain bars and concrete, 80 lb. per sq. in. of surface of bar; 
where adequate mtchanical bond is provided the stress sh.nll not exceed 150 lb. per sq. in. 
of surf;ice of bar. 

RATIO OF MODULI. 

75. The r.itio of nio lulus of el.isticity of concrete to steel shall be considered as 
I to 15. 

76. The allowable tensile stress in reinforcement to be 16,000 lb. per sq. in. for 
medium steel and 20,000 lb. per sq. in. for high elastic limit steel with adequate 
mechanical bond. 

77. The compressive stress in the steel reinforcement to be fifteen times the allowed 
compression in concrete in which the steel is embedded. 

FIREPROOFING. 

78. The main reinforcement in columns shall be protected by a minimum of 2 in. 
of concrete, reinforcement in girders and beams by li in. and floor sl.-ibs l^v 1 in. 

.H2 



[& 



.CONyreiKTJONAl.l 
E.NOINt-L.RlN<i — j 



THSTS. 




TESTS ON REINFORCED 

CONCRETE CONDUCTED 

IN GREAT BRITAIN. 

PART Vlll.i 



/ ' "it sft'€n articles of this series JppejreJ :n our Mj'j, September, Nox'ember, /jriu^ 
Febru.iry, Mjrch and April numbers respectt'vety. The follotving particulars of tests 
n(yw presented, and further articles 'Will appear from time to time, — ED, 



UNITED KINGDOM FIREPROOFING COMPANY'S TESTS. 

A test oil a floor slab in the Billhead Exchange, Glasgow, Kuistriuled by the United Kingdom 
Fireprooling Co., Ltd., for the National Telephone Co. (Mr. Leonard Stoke.s, F.R.I.B..-\., and Mr. 
Colin Menzies, associated architects), was conducted on June 12th, igo8. The slab measured 
18 ft. 6 in. long from front wall to centre of main steel girder and 1+ ft. 6 in. wide from centre 
to centre of supporting side girders, and was calculated to carry a live load of ij cwt. per sq. ft. 
The thickness of the concrete was 7 J in. over all. The load was applied by means of pig-iron on 
a strip 8 ft. wide in the centre of the longest span, measuring 116 sq. ft. in superficial area. The 
deflections were read by means of a simple lever apparatus placed at the centre of the span, which 
multiplied the actual deflections by four and recorded them on an indicator placed clear of the slab 
under test. The concrete of which the floor was made was composed of i part Portland cement 
to 6 parts aggregate, this latter consisting of 2 parts sharp sand to 4 parts hard burned chnker 
broken to pass about a J-in. mesh sieve. The floor was concreted on May 7th, and was thus 5 weeks 
old when tested. The following deflections were observed between 11.30 a.m. and 12.55 p.m. : — 



Total .•\ppUed Load 
in lbs. 
9,296 
19,040 
29,344 
38.304 
47.30S 



.Actual Deflection 
in in. 



Si 



On the remo\'al of the load the indicator returned to zero, and there was no evidence of the con- 
crete cracking or of deterioration of any kind. 

Other tests were carried out on October loth, 1908, at the Salford Royal Hospital, of which .Mr- 
John Ely, F.R.LB..\., is the architect. One was on a sohd reinforced concrete floor slab to a corridor 
of 5 ft. 6 in. span. The thickness was 3J in. over all, and the reinforcement consisted of | in. diameter 
steel rods at 14* in. centres. The area loaded was a 3 ft. width right across the span. The 
floDr was made with concrete composed of 6 parts breeze to i of Portland cement. The floor was 
designed to carry a safe super load of 80 lb. ; the test load was 240 lb. per sq. ft., which gave 
a deflection of ^V in. The deflection was measured by a lever arm multiplying the actual deflection 
by three. The second floor was in one of the rooms, and was of hollow sound proof construction, 
consisting of breeze concrete tubes 7 in. deep by 3 ft. wide, with concrete beams moulded in situ 
between 3 in. wide, thus making 3 ft. 3 in. centres, with a concrete fill composed of 6 parts 
broken brick to i part Portland cement over all, making the total depth 8 in. The span was 
12 ft. between lintel at one end and wall at other. The area load was 6 ft. by 6 ft., each end of 
the loaded portion being 3 ft. from the support. The reinforcement in each beam consisted of four 
S in. diameter steel bars. The floor was designed to carry a safe super load of 80 lb. per sq. ft. The 
test load was 240 lb. per sq. ft. of area loaded, and the actual deflection was /^ in. ; this deflection 
was recorded by a lever arm multiplying actual deflection by three. 



3+.^ 



TESTS. 



[CONCRETEI 



:^ te.t on a solid flo >r c:,nstrL>cted at Epps' Cocoa Factory, by the Uuited Kr^dom Hireprooftng 
r Ltd (Mr E T Hall V P R I. B.A., architect), was also conducted m 1908. The span was q ft., 
the: thickness' of 'floor 4i'm.. composed of 6 parts breeze concrete to r part Portland cement, w,th 
2 ,n of granoUthic finish ov.^r. The reinforcement consisted of 5 in. diameter bars at loj in. <-entres^ 
The'area loaded was a 10 ft wi Jth right across span. The floor was designed for an inclusive load of 
336 lb per sq ft., and the test load applied was 448 lb. per sq. ft,, which gave a deflection of i in. 

^ floor constructed bv the United Kingdom Fireproofing Co., without centering, at the London 
& Toint Stock Bank, Kingsway, London (Messrs. R. Creese, Harrison & Sons, architects), was tested 
in 1908, and consisted of terra-cotta tubes i ft. 6 in. wide and 7 in. deep resting between the con- 
crete beams 2 in. wide at the top and splaved out on the under side, cast previously at he firm s 
vTrd -(these beams, therefore, bcins'at 1 ft. ,« m, centres^ and a concrete fillmg over nil, makm. 




the t0t.1l depth 10 in. The reinforcement in each beam consisted of one J-in. diameter rod and 
two ,= -in diameter rods, the first mentioned being cranked up at the ends to reinforce against shear 
stresses The composition of the concrete was composed-in the beams-of 6 parts breeze to i part 
of cement, while ,n the filhng over the tubes and beams it was proportioned 4 parts of broken brick 
to I of cement. The clear "span of the bay tested was 9 ft., and the area loaded was 17 ft bv 
9 ft. The floor was designed for an inclusive bad of ij cwt. per sq. ft., and was tested with il cwt. 
per sq. ft. super load. The deflection recorded was j'; in. 

Ao experimental test of a somewhat similar floor was carried out on April 8th, 1908 at the 
works of the United Kingdom Fireproofing Co. at Alperton. The floor was one of 24 ft. clear 
span, and was 12 in. deep. The construction is shown in Fi.c S3. Two identical floors, each 12 ft. 
wide were constructed in the last week of December, 1907. One, as a prelimmary test, was loaded 



344 



M 



JaD 



TESTS. 



with a distributed luad uf 85,000 lb. about the beginning of March. This caused some deflection, 
.111(1 at the day of the test was removed on to the other^floor.twhen it was found that nearly all 
the deflection was recovered. The Hanr was made of granite compete proportioned 4 parts crushed 
Leicestershire granite, i part sharp sand, and i part Portland cement, of " Ferrocrete " brand, 
supplied by the Associated Portland Cement Manufacturers (1900), Ltd. The tubes were of similar 
concrete, and measured 3 ft. wide by 7 in. to 7! in. deep and 12 in. long, their thickness varying 




li.tweeii ij in. and 2 in. The floor rested upon blue brick piers well strutted to prevent overturning 
The section of each reinforcement was ij in. by 1 in., so that the total section of steel in each 
beam was 5^ sq. in. The material was mild steel having a tensile strength of about 28 tons 
ultimate. The reinforcements were cranked up at various places to resist diagonal tension stresses. 
The floor was designed to carr\- a super load of j cwt.. with a factor of safety of 4. The floor was 
given I in camber, and the centering consisted of members strutted from below placed under the 




beams only, the tubes between forming a permanent centering. The deflection was read on the 
sliding scale as each layer of bricks comprising the load was applied. These bricks varied in weight, 
and the loads recorded are therefore only approximate, although an effort was made to obtain the 
a\erage weight fairly closely. The load was at first applied on a centre strip 7 ft. 6 in. wide across 
the clear span. The deflections under this partially distributed load were as follows : — 



345 



TESTS. 



[CQNCBETE] 



Total Load 
Distributed. 

lb. 
8,000 
16,000 
24,000 
32,000 
40,000 
47,600 
55,200 
62,800 
70,400 
78,000 
85,600 
93,000 



Centre Deflection 
at Middle. 



J bare 



'Centre Deflection 
at Side. 



i bare 







Lonqitutliiwl Se<ti'in <,f Acui/niThjue/its 



Detail i,f Beam 



-3 li " / J ->•- 



- 'oj — — /J' 

C \ 



Detail of Relnforcemenls 




OR Tested. 

. WOKKS. Al 



After this it was decided to load the whole area of the floor with bricks, and therefore the bricks 
were laid on the side portions to a height of 12 courses — i.e., to the same height as the middle portion 
had been carried. M this point the total load upon the floor was 127,500 lb., the deflection in the 
middle being 2\ in., and the deflection at the sides 2 in. Bricks were now thrown on the top and 
centre of the load without any attempt at stacking. The deflection gradually increased to jJg in. and 
2\ in. at the sides after the total quantity of bricks available had been placed upon the floor, weighing 
in all about twelve tons. The loading was discontinued about 4.30 p.m., and during the night the 
floor gave way without any extra load being added. .A few diagonal cracks were developed near the 
supports, but the shear reinforcement appeared to act satisfactorily. Cracks developed on the softit 
of eachof the beams, but these were not at all wide. A certain amount of arching, no doubt, occurred 
in the load, but the bricks were stacked in such a manner that the layers did not bond very much with 
each other. 

346 



THSTS. 

SIDEOLITH TEST. 

A beam rciiifi)rccil with section of " skeleton steel " was tested on J line I7tli, icjog, at BiriniiiKliain 
University for Messrs. Sideolith. 

The beam was lo ft. by 9 in. by 10 in. deep, and made of concrete composed of r part cement 
2 parts sand, and 3 parts aspregate graded from Jin. downwards, reinforced with one " skeleton 
(Section F., see Fig. 54) weighiii;; j.S lb. It was tested on a span of ft., supported on rounded 

"skeleton " Steel Reinforcement . Seclio/tU 



^ 



XX X 



A 



steel knife edges' and loaded in the centre through an iron plate 5 in. wide with two thicknesses o 
millboard packing. The load was applied vertically, and the beam carried its own weight in addition. 
The result was as follows:— 

Load when first Crack 
No. of Beam .Mark on lieani Length Weight was noticed Breaking Load 

.1 H.S. 10 ft. 860 lb. 10,820 lb. 10,820 lb. 




It will be ob^er\ed that no crack was nolic ed until the breaking load was reached. 

This beam was one of a series of tests with beams variously reinforced with other methods, and gave 
a better result — viz., 10,820 lb. as against 10.280 lb. for a similar beam reinforced with 52 lb. of metal, 
this latter beam also showing signs of cracking at 6,160 lb. Fig. 55 shows the state of the beam 
when removed from the testing machine. 



.U7 



THE CONCRETE INSTITUTE 



ICONCBETEJ 




RECENT VIEWS ON 
CONCRETE AND REIN- 
FORCED CONCRETE. 






THE CONCRETE INSTITUTE. 



// /5 our tntention to publish the Papers and Discussions presented te, 
eties on matters relating to Concrete and Reinforced Concrete in a cone 
uch a manner as to be easily a'vailable for reference purposes* 
The method lue are adopting, of dividing the subjects into sections, is, 
J departure. —ED. 



A MKETIXC. of Ihv CoiKTctr In-,litutc was held at the Roval United Servio- Institution. 
Whitehall, S.W., on April 2i>t. 

The paper on this occasion was read by Mr. Sidney H. 
Surveyor to the Hampton Urban District Council, and w 
(if it and of the discussion wliich followed. 



Chambers, Eng^ineer and 
e are sjivinsf a summarv 



THE EFFECTS OF SEWAGE AND SEWAGE GASES 
ON PORTLAND CEMENT CONCRETE. 

By SIDNEY H. CHAMBERS 

(Engineer and Surveyor to the Hampton Urban District Council). 

Mr. WilliLim Dunn, F.R.I.B.A., Menihcy of Council of the Institute, presided. 

MR. SIDNEY H. CHAMBERS, Reader of the Paper. 

I'liE subject of the present communication, the author stated, was one in regard to 

which it might be assumed that the available evidence was either inconclusive or of a 

more or less negative character. For, notwithstanding that cases were on record of 

destructive changes in tanks and sewers, the opinion tended to prevail that when the 

concrete construction was sound no marked disintegration need be anticipated, either 

from sewage or from its emanations. 

The author's experience, however, did not support this view, and it was to the 
elaboration of this, the positive side of the question, that he desired to direct attention. 
During the last five or six years he had had very special oi)portunities for studying the 
problem. 

In order to be in ,a ]_Hisition to more fully appreciate the disintegratory changes 
occurring at Hampton, and the deductions drawn from them, the author thought it was 
necessary to describe, even though briefly, the installation in question, and to state the 
character of the sewag"e, as well as to outline the nature of the materials used in the 
construction of the tanl< and clianntls. 

The Hampton Installation. — 'I'he nature of the sewerage system was water 
carriage, primarily flowing by gravitation, ;ind, secondarily, raised by plenum pneu- 
matic power. The sewerage was entirely and completely on the separate system. The 
installation consisted of a screening chamber, two detritus tanks, a hydrolytic tank, 
and triple contact beds, and an air purifying filter. 

The sewage on its arrival at the works was delivered from the rising main into the 
screening chamber, and, after passing through the screen, w;is conveyed by a channel 
to the detritus tanks. From these tanks the sewage entered the hydrolytic tank, which, 
together with the detritus tank, was installed in 1903. The disposition of the tank was 
such that the main bulk of the sewage — 80 per cent. — passed through at a comparatively 
high rate of flow, issuing in four hours as a clarified hquid, whilst the small volume — 
20 per cent. — containing" the deposited matters, was sixteen hours in the tank, .-\fter 

348 



[^ 



HFFHCTS OF SFWAGF ON COSCRRTE. 



lK>\viiifj uvcr the Weil-, (if \\w I'lrsl |K>rtii)ii llic liquid fnlcrcd ;i chaniifl which led to the 
Hcoond portion of llic l;mU, consistint; of four hydrolysinj^ chambers arranjjed in 
sequence, and I'llltd with lart;e Hint stones. 'Hie liquid havini^ taken three hours in its 
passafjc throiif^h th<'se four ehanihers, entered the li>wer ehaimel, which conducted it 
ti> the contact beds. 

The screejiint; chamber, the tank, ami the channels leadinf; to and from t'he tank, 
as .also the elTluent channel of the prim.ary contact be<ls, were covered in. The entire 
installation was ventilated by the hydro-mechanical system of sewer ventilation, and the 
withdrawn gases were purilied by being passed through an air filter. 

The sewage of Hampton was of a strong domestic character. It had undergone 
thorough disintegr.ation by the lifting operations, and by the putrefactive changes 
occurring' in the rising main. It w.is malodorous on its arrival at the screening 
chamber, where, as it left the rising main, it evolved sulphuretted hydrogen and other 
bad smelling comix)inKls. 'I'he liberation of these g.ises constituted a nuisance necessi- 
tating the screening chamber, channels, and tank being covered in,, and a nveans being 
provided for drawing a Large volume of air through them before disch.arging^ the gases 
into the ;ilmospliere. 

The Concrete Used. — The while of t!ie tank and ch.ninels, the author said, were 
constructed of Portland cejiient concrete. The walls of the tank .-ire 6 ft. (> in. in 
thickness at the ba.se, ;uid i ft. (> in. at the top, and are strengthened by lie-rotls ; the 
roof was 6 in. in depth and was reinforced by " exp.inded mel.al," and the ch.innels were 
covered bv 2-in. " Ijidurated " ])aving slabs. The work w.is execuied by d<'partmental 
labour, and the best materials were used. 

The concrete w;is composed of one p.art of Porll.ind cement properly mi.Ked with 
clean water and six p.arts of b.-illast thonnighly free from loam, cl.-iy, mud, or dirt of 
any kind, and no material was .illo\ve<l to Im- Larger than would pass through a 2-in. 
screen. 

The makers of the " Indur.itcd " paving Hags state that they are compnjsed of 
Mouiitsorrel granite chippings, washed and crushed to pass through a .J-in. mesh sieve, 
,inil heavy Portl.and ceinent made by themselves, the raw material for which is obtained 
from the Harrow-on-Soar Blue Lias beds. The materials are mixed in the projjortion 
of one ]>.irt of cement to three parts of granite. , 

Efflorescence. — Karly in 11)05, a few months after the hydrolytic tank h;id been 
pui into use, it was noticed that the riy,>f and walls of the Inilrolysing chambers above 
the liquid level were white or yellowish in api>earance. This efflorescence was not 
crvst.alline in structure, but was of .a ch;dky subsistence, and resembled distemiicrcd 
work on a d.imp wall. On examination it was foimd to be due to a Ihin covering of 
sulphur, which could be easily removed by rubbing. Later the face of the walls and 
the roof in the second p.art of the tank showed signs of. jjeeling, and the concrete 
appeared to be disintegrating. .\ thorough inspection of the installation was thereu])on 
made. 

Disintegration. — ".\t the screening chamber nothing .ipiircciable was observed, 

ii'ilhir at ihr hiylicst waler-level nor on the un<lerside of the roof. The concrete was 
■ Hind, and when struck had a good ring. Immediately .adjoining this chamber was the 
main sewage inlet channel, along which the whole of the gases pass to the main air 
duct leading to the ;iir filter. .\t this ix>int slots were made in the concrete to receive 
a dam; the concrete at the back of the gnxives was found to have disintegrated, 
although the sides were perfectly sound. 

Further along this channel it was observed that the greatest disintegration had 
taken place on the walls at the liquid level. Owing to variations in the flow of the 
.sewage, the level of the liquid in the t.ank and channels rose and fell ; thus a certain 
area of the walls was constantiv being immersed in the sewage and then exposed to the 
air. This area was, consequently, even when not immersed, much wetter than the 
part of the walls which was always above the level of the liquid. The latter area at this 
|X)int showed erosion, which, however, had not penetrated so deeply as that at the level 
of the liquid itself. .At the liquid level there was a deep groove in the concrete, and 
above this the face of the work had bulged out and lost its nature. 

349 



THE CONCRETE INSTITUTE. [OQNCBETE] 

The first portion of the tank, i.e., the h_\drol_\lic tank proper, appeared to havt- 
suffered very little. The walls and roof had only the slight sulphur deposit. .At the 
liquid level, which varied less than in the channel, there was a slight erosion. TTie 
second part of the tank, i.e., the hydrolysing chambers, was found to have suffered in 
places to a marked degree. It was observed on breaking through the erosion on the 
surface that the concrete at the back was moist, soft, and gritty. .Also, it was noticed 
that increased dampness constituted an important factor in the destruction of the 
concrete, for the lower parts of the vertical faces of the beams supporting the roof were 
more affected than the up]X'r ]>arts. The lower portions of the vertical walls of the 
tank also were more eroded than the upper. .\t tlie liquid level the concrete had been 
severelv attacked, and a deep gnH)ve existed in it. 

Analyses of Concrete in Hydrolytic Tank. — Two samples of surface concrete 
were taken above and bi-li>\\ tin- liquid livcl, and tlie following was the result of the 
analyses : 

Below Liquid Leiel. \hove Liiiuid Level. 
Sound. Unsound. 

.Ap|)earance ... ... ... ... ... Grey White 

Texture Hard .Soft 

Ratio cement to sand ... ... ... ... 1:2 }, : 2 

Sulphate of lime in cement ... ... ... Trace 66 per cent. 

Considerable Deterioration. — The s.mie pronounced effect was to be seen in con- 
nection with tlie concrete blocks, which were grooved to receive sliding boards and 
project above the liquid level; these blocks had in many instances crumbled away to 
such an extent as to be almost shapeless. Recently these chambers were emptied, and 
it was found that the concrete below the liquid level was perfectly sound and in a good 
state of preservation. 

The lower channel conveying the liquid from the tank to the contact beds revealed 
the same characteristics as were observed in the iip]>er channel, but the portion at the 
liquid level was vrrv much more marki-dh .illeeled. 

Analyses of the Disintegrated Concrete in the Channels. — Samples taken of 
the lining of the sides and covering gave the folli>wing an.ilyses : 

R.itio. Sulphate of Lime in 
Cei.ieni, Sand. Cement. 

1. Concrete at varying liquid level ... ... i i 70*26 per cent. 

2. Underside of slab forming covering •••5 i 74'6i F*"" cent. 

The air duct taking the gases from the effluent channel of the primary beds and 
communicating with the tank outlet channel was found to have a coating similar in 
appearance to that observed on the underside of the covering to the channels. 

Analyses of Concrete in .Air Duct. — .\nal\ses of this coating were made, with the 
following resulis : 

Ratio Sulphate of Lime 

Cement. Sand. in Cement. 

L'nderside of slab forming' covering of air duct... 2 i To'T' 

Conversion to Sulphate of Lime. — The point to observe in the above analyses 
was the conversii>n of the lime in the cement into sulphate of lime, the sulphur being 
obtained from the sewage flowing through the tank and channels, as well as from the 
gases expelled from the sewage, and contained in the air withdrawn from the several 
jjarts of the installation. 

Suggested Explanation. — Much thought had been given to the explanation of the 
loregning observations, and it had been concluded that the effects had arisen from the 
putridity of the sewage and the oxidation of the putrid products by the air supply. 
The main erosive effect was at the varying liquid level, and was there dependent upon 
the amount of sulphuretted hydrogen in solution in the liquid. The gas was com- 
paratively small in amount in the incoming sewage and in the liquid in the hydrolytic 
tank, and increased as the liquid passed through the hydrolysing chambers. The results 
of this were especially well shown in the two channels; the alternate wet and dry area 
of the upper channel conveving the sewage from the rising main was less markedlv 
affected, whilst in the Imver channel the coi responding area was severelv attacked. 

350 



..,..^K...N..^j lil'l'liCTS or SI- WAGE OS COSCRHTH. 



Si) with ilu- lui) parts of ihf lank; Ihf first part inlo which the scwa^'c was delivered, 
and wherein roniparalivelv hille piitrefacliiin look place, had not heen affected to any- 
thirifi like the extent that the second part or hydrolysinj.; chanihers had. 

When the level of the liquid fell it left the concrete which il previously covered 
welted with .1 .ic|ui;l conl.iininf^ sulphuretted h\drosien in solution. This wet surface 
was then exposed to the .action of the air supply, which oxidised the sulphuretted 
Intlrofjen with the ])nKluclion of sulphur and sul|;huric acids; these deconi]X>sed the 
concrete, the lime beinjj; converted lin.'illy into siilph.-ite of lime. W'hal the exact nalure 
of the inlernK'diate coni|X)unds was could nol be stated, as none of them had been 
isolated, but it w;is prob.able that the active aj^ent was sulphurous .acid, as it w.as known 
that cement was insoluble in su!|)huric .acid. When the liquitl rose .i^Jain, the d(co:ii- 
posed concrete was washe<l aw.iy <'ilher wholly or in part, .and ;i fresh surfac:/ was 
exposed to action when the liquitl fell ,ii,'.iin. It was the continuation of this cycle 
whith Iril 11. llie fiinn.iiiiii of ihe i,'ro(ives ai the v.aryin;.; liquid level. 

Concrete above the Liquid Level. -Ww erosive effects on the concrete above 
ihe liquid U^vel were deiK-iulent u|K>n the sidphuretted hydroLjen evolved from the liquid 
and mixed wilh the .air supply. Some of this s^'.as w.as dissolved by the moisture which 
was present o.i the walls .and roofs, from evapor.ation and con<lensatlon ; il was then 
oxidiseil by the .air, .and deci>miK>sed the concrete as described above. In this case the 
decomposed conna'le either remained as a co.atin;.; on the surf.aee, peeled olT, or 
cnnnhUd .aw.av. 

Effect on Concrete Tubes. In ordir lo observe the phentmiejion on concreie 
ltd>es. two i|-in- concrete tubes were selected, which were supplied by the makers of the 
pavinjjf slabs previtaisly referred to, and were composed also o^f similar materials in the 
s.ame proportion. One of the tubes was coated with Dr. .Vnjjus Smith's conipositit>n 
(co.il-tar, pitch, linseed oil, .and resin). They were placed side by side in the second 
part of the tank in such a ])ositit>n that they wouki be subjected to the rise .and fall in 
the level of the liquid. .\t low level the tubes were ni)t in conl.acl wilh Ihe liquid, and at 
hii,di level Ihe liquid ros<' lo half Ihe di.amel; r. 

.\fter the tubes h.ad rem.iined in the lank for eiylit nuMiths the\ were i.iken out .and 
ex.imineil. The coated tube did not ap|>ear to h.ave been affccte<l, other than at the 
hit;hest liquid level, where a thin line could be observed, and wfien struck it was fouiid 
h.ard and had a ijiKid sound. It was noticed that there were two areas on this tube 
w ithout any ct>atinij, due no doubt to its h.avinj,' been ])I.aced upon two supports to allow 
it to dry; these .areas were soft on the surface and simil.ar to the unco.ated tube. With 
these exeeptitms the tube appeared to be in as i;ix>d .a condition as when first i>laced in 
the tank. On the other hanil. the unco.ated tidie h.id .1 distinct line at the hitjhesi 
liquid level, which w.as foimd to be soft, .and wheji Lapped with .a chisel h.ad a dull 
sound; the interior of the lul>e which h.ad be^-n iniimersed ap])e,ired soft and h.ad a dull 
sound when struck; the portion of the udie .above the lii|uid le\el was unaffected, and 
whiai struck h.ad .a clear rini;". 

The .author then referred to other c.i^es of disiniei,'raii(>n of Concreie bv sulplnu' 
compoimds. 

Conclusions. — The deductions 10 be drawn from the investigations were th.it the 
gases in solution in sewatre, and those expelled from it, .arising from its decom]x>sition, 
do act injuriously upon Portl.and cement concrete, notwithstanding the fact that the 
concrete- is constituted of sound and goo;l m.ateri;ils, when the f.illowing conditions 
prev.iil : 

1. A high degree of putrescence of the sewage. 

2. .\ moistened surface, which b.eld or absorbed the putrid gases. 

3. The presence of .a free .air supply. 

Further, that in tlie ali-ence of t>ne or other of the .above enumerated factors little 
danger from erosion need lie feared. 

Finally, the author accorded his obligations to Mr. T. Hughes, the manager of the 
Hampton Sewage Works, and to Mr. J. H. Johnston, the chemist, for tfieir \aluable 
assistance in obtaining the necessary material and data for the paper. 



THE CONCRETE INSTITUTE. [CONCRETE] 

THE CHAIRMAN. MR. WILLIAM DUNN. F.R.I. B.A. 

The Concrete Institute existed for the dissemination of knowledge on all matters pertaining to 
reinforced concrete, and Mr. Chambers to-night had done something towards making them acquainted 
with one of the dangers to which the work was exposed. It was not only in regard to waters which 
were highly charged with sulphur or sulphurf^tted hydrogen that d.-^ngers existed, because it had already 
been found that the water in the earth might act in such a way as to disintegrate both lime mortar, 
lime concrete, and cement concrete. Trouble of this kind had been experienced in several tunnels 
in France, with sewage pipes in Algiers, with sewage pipes in Texas, where the brickwork, in the one 
case, and the pipes in the other, were buried in ground containing alkahne waters. He was not 
sufficiently a chemist to offer any opinion upon the chemical changes which took place or the chemical 
conditions which made the matter dangerous. 

There was a communication from Mr. Arthur Collins, the City Engineer of Norwich, who regretted 
exceedinglv his inabihty to be present, and which he would now read : — 

" City Engineer's Office, Norwich, April 20th, loio. 
" In reference to .Mr. Chambers's paper on destruction of cement concrete in the ' Travis ' 
tanks at Hampton, I have some concrete sewers under my care in Norwich which were laid in 
i3oi, varying in interior diameter from 42 in. to 24 in., the total length of which amounts to 
several miles. They were brought into use for carrying sewage about 12 years since, and they 
show no signs whatsoever of deterioration. The main outfall discharges into a pair of concrete 
tanks forming screening chambers, and the concrete in these has not deteriorated. The sewage 
passing through these screens is pumped to the Sewage Farm, where for nearly 40 years it has 
been conveyed in an open concrete carrier, and in this there is no disintegration by chemical 
action. A few years since my attention w'as called to the brickwork of a reservoir built in 
East Anglia in which bricks from the Peterborough district were used. In this case the very 
high-class quality cement mortar was in parts quite disintegrated. I was informed this was 
due to the presence of sulphur in the bricks. A few years ago I was consulted respecting the 
failure of a retaining wall of a circular percolating filter constructed by the local authority of 
a town in East Anglia. The specification required the brickwork to be laid in cement mortar, 
but about 12 raont,hs after construction the wall collapsed. On examining it I found the mortar 
to have no appearance of being constructed with cement, it being similar in appearance and 
touch to that constructed from ordinary chalk lime when kept wet for a prolonged period ; it 
was pasty and had no strength. I recommended that an analytical chemist be consulted, who 
reported the presence of a large quantity of sulphur. It appeared this sulphur came from the 
bricks, which were from the same district as those used in the reservoir referred to herein. 
Various experiences with disintegrated cement concrete work point to any excess of sulphur 
(whether in the cement or otlier materials used in constructing the concrete or introduced after- 
wards) as being very destructive of it." 
Mr. tl. A'. O. Bamber, Assoc.last.C.E., F.C.S., writes as follows : — 

" Portland House, I.loyds Avenue, London. E.C., April 21st, 1910. 
" I very much regret that a previous engagement prevents my being present to-night to 
hear read and discussed the very interesting paper presented by Mr. Chambers. The paper 
is an extremely valuable one, as being a plain record of actual facts rather than an exposition 
of vague theories. 

'■ The subject-matter of the paper is one that has on previous occasions come imder my 
notice, and, in the main, I am in accord with the author as to the probable cause of the defects 
discovered in the concrete being due to the complex action of sulphur compounds, although 
there may be some doubt as to the precise action which takes place. I belie\e that a fairlj' 
warm temperature and moist atmosphere are necessary to produce the results stated by the author 
— i.e., the conversion of sulphuretted hydrogen into suljihuric acid. 

" In this connection the author states that cement is insoluble in sulphuric acid, which is 
not quite in accord with the previous statement that the sulphiu^ic acid decomposes the con- 
crete. Cement in the form of calcium hydrate, in which it largely exists in concrete, is soluble 
in sulphuric acid, the suggestion that it is not. being simplydue to the fact that during the action 
of sulphuric acid on the lime calcium sulphate is formed, which collects over the siu'face of the 
particle; of calcium hydrate to be dissolved, and prevents the further contact with sulphuric acid. 
" Calcium hydrate continually agitated with sulphuric acid is soluble in that reagent. 
" It is possible that the reaction may be brought about also by the combination of the sul- 
phuretted hydrogen with the lime of the concrete forming calcium sulphide, which is oxidised 
to calcium sulphate by the air passing through the culverts. In either case the result is a loose, 
friable material, which is washed away by the passing fluids, again exposing a fresh surface for 
such decomposition. 

■' The remedy seems to be in the formation of an absolutely impervious and smooth surface 
on the inside of the culverts, and in this connection my company are already engaged in experi- 



[a-SoS'^'l.;[n,.^1 effects of sfwacf on concrete. 

iu.iit.il u.mU wall a special preparaliun ul I'nrtla.ul rniicnt to hv used f„r this „„ri)ose I am 
hopeful that iu this way defects such as have been descrihed by the author, and which may ha^■e 
i>ec„ brought about by some special circumstances, mav be entirelv avoided. I receutlv had 
an.opportuu.ty of .nspecting some of the main sewers in I'aris lined with Portland cement which 
show no sign of detenoralion, and I think the author's experience in this connection for some 
reaso.,, ,s somewhat unique, and must have resulted from some special circumstances as such 
def.-cts are not scncra m sewer work constructed in I'ortland cement concrete. In conclusion 
InTi"i p " " ' "" ""' ''"' ™'"^^'*' contribution to the list of subjects dealt with by the 

The ClMinuan thai called on Mr. .ll/re.l HoeMmg, to open Hu discussion. 
MR. ALFRED ROECHLING. 

Concrete was now very larsely used in sewerage and sewage disposal works, and the engineer who 
had to deal with this class of work could not possibly do without that material, whether it be i^, 
simple construction or m reinforced concrete construction. Concrete was used for tube- sewer- 
manholes, tanks-such as septic tanks, cesspits, tanks for the storage of night (low, and hvdrolytic 
or Iravis tanks-and the subject was of the utmost importance as regards the life of the concrete 

Concrete Tubes.-TSlo alarm need be felt by anyone who had been using concrete tubes in con- 



. lucnce of the conclusions of the author, and if his remarks were correctlv understood thev limited 
. n ■ subject to one jjarticular point-very foul or putrid sewage. The point was still furthe^ limited • 
II.. influence varied below the water level, and. further, the influence of verv putrid sewage could 
only be felt when there was a large supply of free air. He thought wherever there was a chance of 
he formation of sulphurous acid concrete should be avoided. Thev had been using concrete tube 
for 30 or .io years, not only in this country, but also in America and on the Continent On the 
Continent of Europe they had been used \ery largely, and some time ago a qucslioii was raised there 
as to what extent these concrete tubes could replace stoneware pipes. It was stated that the sewage 
had a very deteriorating elTect upon the concrete. The investigations were verv carefullv made 
and as a result of the vari.ius observations it was quite clearlv proved that under ordinary condi- 
tions the sewage did not deletenously affect tlu. concrete tubes. There were, however certain condi- 
tions under which concrete tubes ought not to be used, and those were exceptional or extraordinarv 
conditions. For instance, where there were verv hot liquids, say above i-o- 1- or where steam 
was discharged into a sewer, concrete should not be used for this reason-that tlirou-h the various 
parts of the concrete tube, which were heated unequallv. internal forces were set up which lead to a 
crack, and probably in many cases caused the collapse of the tube 

Concrete should n..t be used, at any rate, in immediate contact with 'the discharge of acids into 
.■> tube or sewer. In. one case particularly which he remembered there was a discharge from some 
dyeworks opposite to the entry into the sewer on the other side of the wall, and the concrete of the 
sewer had been eaten away, the matrix had disappeared, and the pebbles were Iving looselv on the 
bottom of the sewer. Then there was a case where the ground through which the sewer was laid 
contamed a great number of pyrites, sulphide in some form, in consequence of which, bv the forma- 
tion of sulphurous acid, eventually the concrete tube collapsed. There was another case within his 
own knowledge of a reservoir for waterworks purposes constructed of concrete made with furnace 
lime. They would agree with him that that was a very imjiroper material to use, especiallv as in 
many cases ,t contains sulphur. In 10 years the concrete collapsed ; it got soft in places, and 
crumbled away in others. With the exception of these special cases, however, there was no need 
to (ear that concrete tubes would be attacked bv sewage or sewage gases 

He had examined septic tanks, and had also' observed cesspits that had been in use for a number 

fu^Z' f .17"^"".',''"' •'::''"f^"y '"'''<=' ^"'l ""y good. He would suggest to the author 

th.it the cause of that had been the absence of a great amount of free air. In Hampton thev had 
artihcal ventilation ; they drew the air out. and it might be that in doing so the decomp<,s,tion or 
the oxidation of the sulphuretted hydrogen proceeded more rapidly and more effectively. 

MR. EDWIN AULT. M.I.Mech.E., F.S.I.. M.R.San.I. 
■^ Some four years ago some samples of concrete pipes had been sent hiin for report upon the cau^e 
of corrosion. The pipes were made with good cement and clean, sharp sand, which on analvsis of 
a new pipe showed a proportion of i to ij throughout. The pipes were 4 in. internal diameter; and 
had walls rather more than i thick (077 in.). They were of the ordinarv spigot and socket shape, 
and were of a length of 24 m. in the work. The quality of the pipes might be judged bv the fact 
that under an internal hydraulic test they stood 100 lb. pressure per sq. in. when water began to oose 
out of the pores of the pipe. The pressure was then slowlv increased to 120 lb. per sq in when the 
pipe failed by cracking at the spigot end. ' 

The sample of neat cement used in the manufacture of the pipes gave, after 2S days, a tensile 
strength of 6783 lb. per sq. in. Cement mixed with 3 parts of the sand used in making the pipes 

353 



THE CONCRETE INSTITUTE. [CONCRETE] 

gave, after :!S days, a tensile strength uf 360 lb. per su. in. The fineness of the grinding ol the tement 
gave only 3'2 per cent, residue on a sieve having 32,400 meshes per sq. in., and o-5 per cent, on a 
sieve mt 5,776 meshes per sq. in. The pipes were used for the conveyance of sewage, and the corrosion 
appeared only on the upper or aerial parts of the pipe.s while the invert or lower parts of the pipe, 
which were covered with sesvage, were found to be unaffected. Analysis of the white incrustation 
on the upper part of the pipe examined showed a large excess of sulphur anhydride (SO3) in the form 
of calcium sulphate. 

Curiouslv, an experiment with fumes of sulphuretted hydrogen directed on the pipe had no cor- 
rosive action. This was probably due to the absence of moisture. The portion exposed to the 
fumes turned black, which was attributed to the action of the ferric oxide contained in the cement. 
By suspending pieces of pipe in the fumes of sulphurous anhydride (SO,) the calcium carbonate was 
changed into calcium sulphite (CaSOj), w-hich subsequently, on exposure to air, changed into calcium 
sulphate (CaSO^). The pipe; were in use in a tropical city, but our information did not show whether 
the cement pipes generally were affected or only those in certain districts. Bearing in mind the 
greater intensity of the decomposition of organic matter in the tropics and the great humidity of 
the ordinary atmosphere of this particular city, and. also the fact that the sewage flowing through 
was a domestic one of great strength, and also bearing in mind the later experiences which Mr. 
Chambers had so lucidly set forth in his paper, he had not the slightest doubt that the corrosion of 
the pipes mentioned was due to the same causes as that which had been experienced at Hampton. 

MR. D. B. BUTLER, F.C.S., Assoc.M.Inst.C.E. 

-■Vbout five or six years ago he had to examine a piece of concrete pipe, likewise in the trtjpics, 
which had been used about five or six years, and in this case, too, the conditions seemed exactly 
parallel to the case which the author of the paper had brought forward — that is, the concrete was 
corroded. The pipe was about 6 in. internal diameter and about r in. thick, and at the top of the 
pipe the thickness %vas reduced to J in. There was a coating of white deposit on the top of the pipe, 
which he likewise found to be largelv sulphate of lime, and from analyses he made it was evidently 
d.ie to the corrosion of the sulphuretted hydrogen from the sewage. Nearly all the alumina in the 
cement, this particular white deposit, disappeared : there were only practically silica, lime, and sul- 
phuric acid. His explanation was that sulphate of alumina was formed, which the moisture from 
the sewage had caused to dissolve — it is a very soluble salt indeed — and it had run down the side 
of the pipe into the sewage again. He made some experiments at that time by treating some ordinary 
cement briquettes, composed of 4 of sand and i of cement, partly immersed in a solution of SgS 
'sulphuretted hydro.gen), and half in and half out of the water. The part of the briquette which 
was in the water did not seem to be affected, except to turn black, but the part which was in the gas 
was practically in four or five days disintegrated. A further experiment, by exposing briquettes 
entirely to the gas for two or three days, had a most peculiar effect. They swelled up to nearly 
25 per cent, above their original size, and became quite rotten, showing very clearly that if cement 
is exposed to very strong H,,OS gas in a damp atmosphere it is disintegrated very readily. It 
seemed to him that if this pipe could have been better ventilated, so as to avoid the gases acting on 
the cement, this would not have happened. 

One thing which rather struck him was the coarseness of the cement mentioned in Mr. Butler's 
paper. It was apparently only five years ago. If the residue on that sieve was as much as 27 up 
to 30 per cent, of the residue on a 50 sieve, and No. 3 sample is 25 per cent., that showed the enormous 
strides which had been made in the last few years as regards grinding 



MR. ARTHUR C. JAMES, Assoc.M.Inst.C.E. 

Engineer and Surveyor to the Cniys Urban District Connci'. 

He had charge of stime sewage works, where practically the whole of the tanks and other works 
in connection with the sewage treatment were formed of concrete. The districts through w'hich the 
sewage fiowed were very flat, and when it arrived at the works it was not only very strong, but was 
highly concentrated, and rather in a septic condition, giving off a good deal of sulphuretted hydrogen 

The tanks into which the sewage flowed were formed of Thames ballast and cement, 4 to i concrete, 
and they have now been in use between 15 and 16 years. The concrete was absolutely as good as 
the day it was put down. There was no sign of deterioration whatever. After having been pumped 
from these tanks, the sewage flowed into some septic tanks, also of concrete, in which there was no 
sign of deterioration at all. It therefore seemed that there must be something in connection with 
the construction of the material of which the concrete was formed at Hampton which led to the action 
mentioned by ilr. Chambers. 

MR. WILLIAM G. KIRKALDY, Assoc.M.Inst.C.E. 

He knew trouble arose from any sulphur compound in the aggregate. Where breeze concrete 
had given way, it had been found to be attributable to the presence of sulphur. 

He thought, perhaps, something might be considered on the question whether they could get the 

.15 4 



Ife-ENoiNEEBiNo—J J^l-I'hCJS () i' SJi.\\ AGI£ O.V COSCRETB. 

concrete as dense as possible. TiuMnorc iii)TiiTvi,,ii^ .1,,,, • 

dense, the better it would rcis, Hrwo ered n t ', 7, ' , ' "h- <--m,rc,e. the n.ore ,„echanKally 
Whether it would be feasible to ^.d a;:::';;::;;t , o^t' ^ he ^r ^^^"00^ ..een n,e„ti<.„ed, 

concrete up with surface dressinc^i but it ,ni,.l.t i,„ 1 . . concrete One did not like to doctor 
iaterestin,^ if the che.nists woll Sl,nv ,hL u, '^■«""»-'« >" ™rtam cases. It would be very 

MR. E. AULT. 

..l.o^'Kn"'d''1^d';he^ ';"""""■ "' Tis"! "—'"■' "-t the Hampton tank stands about „ cr „ f, 
ground, and there was no sign of leakage anywhere around the walls, r i, .1. 

MR. E. P. WELLS. J.P. 

..e^.^!^X -— --rn;:^e;:;:,::^:^;:i'':,!d^h:t n:::ur^;;:r"i t "■■" •"' 

generally in the ..^::z:7z^:L:S:'zT. Sx ::':rzz Y'"t ''''-''• '-') 
:"S;r:r:ta^^f:;:rf;^-^bL^^rd '- --»' --■ ^■" -^■erlt.^r:.;;' 

With sulphuretted h clro^etand Ts tfe ^l":; "t'fe^^^^^^^ V I"'""' " "■" ''''''' "'*=•">' ^'■"'""' 

eating away the surface by^ule l::r,n\rn^rsS;a.V:f' lin::''^'' ''''''"' '''''' °" '"^ »— ' 
and^Z; l^r^rUTt::^.::^:::;::::::;:-^--;;:- '-ased the .rength «, concrete. 
scttins concrete csoeciiMv in «^w,.r ,., t V ' ' ""^ necessary to get a very quick 

sener^llv the practice "n Tule s"';:! wirh'Th""'""" "^''"'-'"-''^ "-<= "eing made,'it\vas 
a rapid setting and also hlrdeilS ""'"" '"''"' "' """^ "••'"^" ™' <=-'"'^^<' 

good *ar.::::b:d"^:a::^i,l:r':^ xr '" '"Tr, t ^^"^^'"^ ■" "-^ "="-' --'' "•- -- => 

about Hampton was ^^ btiuse' if s, ch wa! h"' k^'^k' '"''^" '"'"' '"^ «'"^='-^'-"^ --"d 

acted upon";, very rap^S teTttsV h^'l roU^ITalHra V.^^^^^ '"=", '^^. ^""""■^ 

not fit to be used for concrete at all Hampton was extremely dirty, and 

.■..™ .„,. „„ .,„ J,, „.„„,;• tr, j,'i r„ : r™; ,r °"'' ""■"■ """ "" 

breeze, then the action became intensified. '^ ' " "' °'"''^ °' '"■"" '" '^e 

MR. HERBERT E. BROOKS. 

In the course of practical connection with cement work n ,rr..r „ f u .-« , 

arose were due to carelessness- in f^^, . "" "' "'"^'^ ^ S^eat many of the difficulties which 

When they got concrete h^w^ , t ^""'"T"" ' """' "'^'''' °' "■"'""'" ""e concrete properly, 
absolutely-full o "id, and t en f thTeT ' """^il' '^^'""^"^" "'''<'" '' "'^ ' '° "■ " --'<^ ^^ 
the destruction wrought\vas infi! Ue ' morV 7^"':, ''"'°"' '""'''' ™"''"^ '"'" '^™'^'=' -"" it. 

He had discussed'manv in e w ■ h Mr \-,>o^ Z T^: ™'"P'«- 
case of disintegi-ation there and he vtr V u k . "'^''our Engineer of Aberdeen, the well-known 
of the destructi:,n wh. h "^s ^fou ht herem the hr,?' " ''''""'' '""^ °P'"'^° '"^^ ""« -^" -"- 
which the concrete was put into place ™ ''*'" ''''" '^' '°'^"'' unsatisfactory way in 

destructive action of seCf and acids ^":^-L"=hterfelde, Berlin, wh. investigated the case of the 
of h,s investigation was lit-fn On l,okn»^h T,T '°"""' "'""'■ ^^ °^"^^ ^^'^"^d °' 'he result 
a number of towns in G:;rnv wL re th^offia^al'f re^on'edT' '' 7' 'T''^' " ""^ '''' '"^'^ ''^^ 
of age, and in summarising the resuTs o the ren , «' n''°l'°"''''''P'P''"^''='"^*°>''^^" 
authorities in charge of those pl.aces pa ealv the who ' T^T' "^T""'^ ''°'" '"' """"'^'P^' 
..ve action of sewage upon -».,;/=;' 00^::*^::;:^ ^td ^:'^:^';:^ ^^^l;--- 



few in number. The 
355 



THE CONCRETE INSTITUTE. [CDNCREJ^ 

concrete Union of Germany, in discussing this very question, had laid great emphasis upon the 
necessity of a very careful ramming of the concrete work which came into contact with sewage, and he 
thought that the dangers which existed from the chemical actions which had been alluded to in this 
discussion would be very greatly minimised, if not altogether successfully resisted, by a very careful, 
complete, and thorough ramming of the concrete, and also if care were take:i not to make the 
concrete too poor. As to filiing the voids, one of the best, most successful and cheapest ways of 
filling the voids was with the cement itself, and it was a good deal better to have a rather richer 
mixture and prevent your deleterious fluids from penetrating into the fissures of the concrete at the 
outset than it was to have a dearer remedy afterwards. 

THE CHAIRMAN. 

They had had a most interesting paper and discussion. They had not united upon the remedy, 
but the cases of injury seemed comparatively rare, and they might take precautions against such 
injuries as did arise by a better class of concrete, and also by inquiring as to whether there ought to 
be discharges of hot water in the sewage pipes or a very strong domestic sewage going through them. 

It was suggested that an increase of ventilation would be a benefit to them. He thought that 
in this particular case which had been described to them it was the presence of the air passing through 
it which made the thing not work. They knew, at any rate, that in cesspools, where there was very 
strong domestic sewage coming from houses, the cement lining did not perish, although the sewage 
was of the very strongest kind, because in most of those rases there was very little change of air; 
they have become, in fact, septic tanks. 

He had great pleasure in putting to them a vote of thanks to the Speaker for the j^aper he had 
bn>ught before them — (applause) — and would call upon .Mr. Chambers to reply. 

MR. CHAMBERS. 

Thi Lecturer's Replies : — He wished to thank them \erv much for their vote of thanks, aiid also for 
the verv kind way in which the members of the Institute and others had received the paper. He 
would prefer to communicate his replies in writing later on, but he would now take as manv 
of the questions in hand as possible. 

With regard to the temperature and other abstruse chemical elements, raised by Mr. Bamber. he 
would ask Mr. Johnson, their chemist, to answer them later. 

Of course, in the main, he thought his conclusions answered many of the points raised by the ciiTerent 
speakers. He had said that the gases in solution in sewage, and those expelled from it, arising from 
its decomposition, did act injuriously upon Portland cement concrete, notwithstanding the fact that 
the concrete was constituted of sound and good materials, when the following conditions prevailed : — 
(i) high degree of putrescence of the sewage ; (2) a moistened surface, which holds or absorbs the 
putrid gases; (3) the presence of a free air supply. Further, that in the absence of one or other 
of the above-enumerated factors little danger from erosion need be feared. Corroboration had been 
found in the remarks of a few of the sjieakers, notably Mr. .■^ult and Mr. Butler. Mr. Butler particularly 
described the erosion in a more forcible way than he (Mr. Chambers) did himself. He referred to it as 
a bulging out and a swelling. As a matter of fact, that was just what had happened. 

With regard to the analyses and tests of the cement, he had said that for the cement supplied the 
specification was drawn before the British Standard Committee had drawn up their Standard Specifica- 
tion, and the tests were well within the specification. 

He did not altogether agree with Mr. Wells with regard to the Hampton ballast. There were 
different kinds of ballast at Hampton, as well as different kinds of granite in any local district, but it 
certainly was very dirty. Precautions were taken against that, and only clean was selected, and also 
the precaution was taken not to use any ballast that was near the site. The concrete was also well 
rammed. He would like to mention that not only was there sulphate of lime formed on the concrete 
thev made themselves, but the percentage of sulphate of hme was very high on the slabs made with 
the granite aggregate coming from Leicestershire, so it was not altogether the ballast or the material. 



356 



f&g;?.S°ESt!S^^ WHARF AT Divas. 

NEW WORKS IN CONCRETE 

AT HOME AND ABROAD. 

Under this heading reliable information "will be presented of neiv "works in course of 
construction or completed, and the examples selected tuill be from all parts of the titorld. 
It is not the intention to describe these tvorks tn detail, but rather to indicate their existence 
and illustrate their primary features, at the most explaining the idea which served as a basis 
for the design, — ED, 



REINFORCED CONCRETE BRIDGE AT COTTA. DRESDEN. 

As .1 lii)iuis])ifi-i' lo this isMic \vc prcM-ni an ilkislration oi a ri-in force d concrete 
hridgo which was crccteil on the Miillcr sysleni iif horizontal {,MrdLT bridiifes, by Messrs. 
Riid-\V(ilk\ of l.t'ipzijj;'. 

The bridge serves as a foot bridije over llie Weisserilz al ("o(la-I)rei*den, and has 
a span of 85 ft. 

Owiny; lo llie pressure on our sp.ice, we must defer i^ivinf,' delailed particulars of 
lliiv worU ill lliis issue, hul drawing-, and a leehiiical descriplion will .apiK'ar in .a 
lau r number. 



WHARF AT DIVES, FRANCE. 

.\ wh.uf is at present in course of ireclion for the Soci<"tt^ d'Electro Metallurgie de 
Dives, Calvados, France, and we think .1 description of the novel methtxl of making 
ihe piles and sheet ]>iles combined will be of interest to our readers. 

The work is beintj carried out aceordins^' to the new methods of .Messrs. Kdmond 
Coignet and Kavie'r, of Paris. 

.\ glance ;it the design and photographs of the pile in our illustrations will imme- 
diately show the method of construction, and also the advantages offered by this new 
arrangement, which has been patented in France and various other countries, and 
recently in l-'ngland by Messrs. Edmond ("oignet, Ltd. 

The wh.arf consists of a frontage of about ujo ft. in length. The main piles are 
driven at a distance of approximately 7^ ft. centre to centre. 

These principal sheet piles, which measure 10 in. by 12 in. in section, are coni|x>sed 
of reinforced concrete, built in th? m.anner of a ("oignet pile, with round b.irs ,ui(l 
stirrups in comhin.iliun witli s|)iral winding. The length of the pile is appro.ximatelv 
2bi ft. 

The panel or sheet pile, which is attached to the main body of the pile by means of 
a strong meshwork, me.isures appro.ximately iS ft. in height by 4 ft. in width, with 
a thickness of 5 in. 

These piles, in combination with the sheet pile, are driven by a steam monkey 
in the same manner as an ordinary pile in reinforced concrete. 

The main sheet piles are first driven, and the intermediate sheet piles, which are 
about 3 ft. 6 in. in width, are ne.\t driven with their edges resting on the inside of 
the principal piles, in order to form a complete retaining wall for the filling up, which 
is to be placed behind them. 

The main piles are maintained in position by land ties, fi.\ed to a longitudinal 
reinforced concrete beain buried in the solid ground, in order to form a proper 
anchorage for the wharf front. 

.\fter all the piles have been driven in their proper position the heads are stripped 

F 2 .357 



NEW WORKS IN CONCRETE. 



iCQNC ^rEl 




35B 



I y, lt>NM IJIJCTIONAl.l 
1'^ LNIilNt-l-KlNli —J 



WHARF AT I)l\-I-:S. 



of ihoir concrt-lf and a Iiiiigiludinal crownint; bt-ani is iiuuiklfd lipcin tlu-so, so as 
to link them toj,'flhcr, forniiiis;- at the same time a copintj fi.r ih.- i.,[. of ih.- wharf 




he invfiitor claims that these piles mav 1 



leat advanta£je. not only 



for the formation of wharves, but also to divert the cour"se of a river'V placins'a 



359 



NEW WORKS IN CONCRETE. 



[CQNCRETB 



row of sheet piles across the current, in such a manner that the face of the sheet 
piles is diagonal to the current, so that the water striking the surface of the sheet 
piles is sent in a different direction to the original flow of the river. 




Durinf 
360 



CONCRETE HOUSE WITH UNTREATED SURFACE. 

the pa^t few years there has been a great deal of discussion concerning 



m 



CONCRETE HOUSE. 



thf |)i-o|Hr Ircaliuent of concre'if surfaces, and the house which we are tlescribing and 
shiiwn nil paf^e _V- should theroforo be of hiterest, on account of the entire absence of 




exterior treatiiit-nt. 
is ditTicult to >ee hi 



1 toigiici Slieet 1>iIl. 
Wharf at Dues. 

huildins- certainly shows a very pleasing- appearance, and it 
y treatment could improve it. If a surface of this character 

361 



NEW WORKS IN CONCRETE. 



(CQNCRETE l 




362 



ry.cc/N.vik>iu honaH 

L'>. LNdlNt.LKlNl. —J 



CONCRETE HOUSE- 



i-, cvf]iUi;illv accepted as appropriate there would be a considerable saviii;^ in time 
and mojiey. 

1 he dwelling is a double house, planned so as to preserve the outlines of a large 
single dwelling, and is thoroughly substantial throughout. It was erected at Ocean 
City, N.J., U.S.A., by Messrs. C"arey and Reed, conlraclors, of Philadelphia. The 
house is 59 ft. by 36 ft. The retjuirements proved at lirsi a very ditllcult i)robleni for 
the architect. The house was lor a small seaside town, which meant e.xix)sure to 
severe storms in winter and hoi sun in summer. It was essential to have the greatest 
economy in space, and it w.is also necessary to keep the cost at a minimum, pro- 
viding, however, for thorough workmanship and weatherproof qualities. After 
careful sliidv concrete w.is chosen as the material best answering the various require- 
ments. 

Another feature of llie house which should be noted from the view of economy 
is the fact th.it the walls are solid and only 6 in. thick. C"onfronted with a great 
• imount of contradictory data on this subject, and so as to preclude |X)ssibility of 
moisture on the inside, it was finally decided to fur and plaster the inside walls with 
the exception of the walls sup|X)rting the |X)rch. These walls are exposed to the 
weather, and have undergone a very severe test owing to the exposed ceiling, which 
is .also the porch floor. During all the winter storms these walls, as well as the 
ceiling above them, have [lot shown the slightest trace of moisture upon the inside. 

Regarding the concrete construction, the walls are carried on concrete footings 
2 ft. wide .-md 12 in. deep. The ftxitings are reinforced longitudinally and transversely 
with i-inch square corrugated bars. At the top of the footing a recess was left to 
receive the wall. The outside forms for the wall were first erected and the window- 
frames fastened in place. Then the inside forms were erected and the concrete poured. 
l-'orms were wired together at intervals of 5 ft. in both directions. The concrete w-as 
placetl one story at a time, but the work was not continuous. When necessary to stop 
over night construction ceased at ;in angle so as to avoid a vertical showing joint. 

The walls were reinforced with i-in. square corrugated bars, spaced 12 in. apart 
vertically and 2 ft. horizontally. The vertical bars were left projecting i ft. above the 
first story in order that they might serve as an anchor.-ige for the second story walls. 
The result is a [)erfect bond and ;in imperceptible joint. Thorcjugh cleaning of the top 
of the concrete at the line of the first story was the only precaution taken to ensure a 
perfect bond, except, of course, careful spading. The entire ground floor of the house 
is a monolith joined to tlie footings. Floor slee()ers were placed on top of this concrete 
sub-base and filled between with concrete of a thinner mixture and subsequently covered 
with the wotxlen lloors. 

The parly wall is entirely concrete from the ground to the roof. The entrance porch 
is solid concrete, including the floor, steps and balustrade. It is g ft. wide and 8 ft. 6 in. 
above the sidewalk level, having a return at one side as shown in the picture. The 
porch is an integral p;irt of the house and built at the same time. The front wall, 
in a sense, starts at the jjorch level, being carried on a reinforced concrete beam. 

The massive concrete chimneys were cast with the house, and, like the porch, 
are an integral part of the house. Flue lining was placed upon the inside and the 
chimneys capped in red terra cotta. 

The bath-rooms have white Portland cement floors with wainscoting of the same 
material all in trowel finish. 

\\'e are indebted to our contempor.arv, The C'f)>iciil .\i;e. for our illustration. 



363 



NEW USES FOR CONCRETE. 



ICQNCRETEl 



NEW USES FOR CONCRETE 

AT HOME AND ABROAD. 

Under this heading reliable information ivill be presented as to ne'W uses to 'which concrete 
and reinforced concrete are put, 'with data as to experience obtained during the experimental 
stage of such new applications of these materials. The use of reinforced concrete as a 
substitute for timber in exposed positions is one of the questions of the moment. Railtnay 
sleepers, telegraph posts, fence posts, etc., of concrete are being tried. Similarly, efforts 
are at present being made to pro-ve that reinforced concrete is an excellent substitute for 
brickwork, where structures of great height are required. ^ED. 



REINFORCED CONCRETE WATER TOWER AT KUCHING 
(SARAWAK), BORNEO. 

Ol'k pholograph shows a reinforced concrete elevated water lanlv. constructed by 
Mr. H. F. Carew-Gibson, C.ininii^slnii.r of W'-nk- .md Siii-\.\-., Sini^apore. 




^ LNC.INLt-KlNG^J 



REINFORCED CONCRETE WATER TOWER. 



The tMfik is i6 ft. dwp by 30 ft. diameter, internal nieasurenients, and has 
a capacilv of about 70,000 gallon.s. The foundation.s are 7 ft. below and the floor of 
the tank i.s 50 ft. 3 in. above ground level. 

The nine legs, each i ft. 6 in. square in section, are reinforced with round 
steel bars wound spirally with mild steel wire, and are braced together twice in their 
height by nieatis of 6 in. by 6 in. ties reinforced in a similar manner. 

Tl-.L' lloor of the tank is SA in. in thickness reinforced witli 3 in. mesh expanded 
steel, carried by beams reinforced with round steel bars and expanded steel. 

The wall of the tank is 7 in. in thickness, reinforced with 3 in. mesh expanded 
steel, square steel bars bein^c -ilso used at inter\'als. 

The tank is line<l with a 1 in. thickness of special waterproof cement plaster, 
laitl on in two coats. 

The roof, of the iii'l.nll:i lv|-, i- of Hilli:iM Hn-ii Wc^od). 



CONCRETE POTTERY AND GARDEN FURNITURE. 

riie illustrations which we present are taken from '• Concrete Pottery and Garden 
I'urnilurc," by Mr. Ralph f. Davison, Assistant Secretary (o the Concrete Aisocia- 
lion of .'Vmerica. 

'nie book is very t.islefully got up, is well 
supplied with illustrations, and detailed in- 
structions are given of how the dilTerenl 
pieces are to be ni.'idc. 

The cha[)ter dealing with colourid 
cements and the methods use<l for producini; 
designs with tliem is [i.articularly interesting, 
and the possibilities of ornamenl.ation willi 
concrete seem unlimited. 

In the chapter on (iarden l-'urnilure there 
are a numl)er of verv efftctive sundials and 
vases, mounted on ornamental petlestals, any 
of which w ould greatly add to the picturesque- 
ness of a g;arden. In Fig. 1 we show an 
artistic sundial made of concrete. If a sun- 
dial is to be placed on a pedestal it need not 
be cemented in place. They are usually made 
of brass or bronze and their weijj^ht is sulTi- 
citnt to hold thetn down. .\ s^ood solid 
foundation must be pre])'ir;d for the pedest.-sl 
to rest on ; and, in fact, .all heavy g.arden furni- 
tm'e should be provided with good solid 
foundations, which should correspond to the 
size of the base of the pi:'ce which is to rest on 
them. 

There .are numerous desii^ns of pedestals 
shown so as to jjive the reader some idea of 
the wide possibilities in design which can be 
obtained from concrete. The book also 
contains a number of illustrations and descrip- 
tions of artistic f'ower boxes, water jars, 
ijarden benches, balustrades and fences all 
made of this material. 

The book contains an elabor.ite descri]:- 
tion of how to make the glue moulds, 01 
flexible moulds, which are extensively used 
in castintj concrete ornaments in which the 
design embodies heavy relief work, such as 
ill the liighlv ornamental table in Fig. 3. 

The method of making: cement pottery 
seems very simple. The first step is to make Fig. 1. CoNCRtTE Slndial. 

365 




NEW USES FOR CONCRETE. 



[CQNCBETEl 



the form to hold the Portl.ind CL-ment mortar, of which cement pottery is made, in 
shape. There are several nielhods of makint;' these forms, but one of the simplest when 




onh ijne article of the same shape is to be used is the use of wire frames. In a former 
issue we sjave an illustration of these frames, one for a square and the other for a 
round piece of pottery. 

Fig. 2 shows two flower vases made of concrete, .and there are numerous other 
exam])les of this class of work. 

This book should certainly prove of interest to both the professional and the 
amateur, and if the craftsman follows the directions given he will find it easy to 
produce satisfactory results. 

We are indebted to the publishers, Messrs. Munn & Co., of New York, for the 
illustrations. The book is copvriijhtcd in Great Brit.ain. 




366 



'EN(ilNH,UlNli ~J 



CONCRETE MIXERS. 



INDUSTRIAL NOTES. 

These pages have been reserved for the presenlallon of jrllcles and rtoles on proprietary 
materials or systems of construction put forward by firms Interested In their application. With 
the advent of methods of construction requiring considerable skill In design and supervision, 
many firms nowadays command the services of specialists -whose -vle-ws merit most careful 
attention. In these columns such vie-ws ■will often be presented in fa-vcur of different 
specialities. They must be read as ei parte statements— -with -which this journal is in no -way 
associated, either for or against — but -we -would commend them to our readers as arguments by 
parties -who are as a rule thoroughly ron-versani -wllh the particular industry -wllhvihlch Ihey 
are associated. ~ED. 



CONCRETE MIXERS. 

TriE careful preparation of the mortar is the most important [Kiint to be considered in 
the manufacture of sui^rior cement articles wliich will be able to stand competition in 
llie marUel, as well as for reliable structures in concrete and reinforcf-d concrete. 

The more completely the different materials have been nii.xed the greater will be 
the economy in the consumption of the binding material. .Most e.\perts prefer lo have 
the mixing done by machinery rather than by hand. The method of working the 
mixer, however, dejx'nds on the nature of the stuff lo be mixed, and the construction of 
the machine must also be adapted to the daily output re(.|uired. .A continuous mixer 
can turn out considerably more in the course of a day than an intermittent mixer, but, 
on the other hantl, the latter gives the advantage th.at the period of mixing can be 
considerably lenglheixd for materials \\liich require it. 



Dyr A 




.\ short description of the different machines manufactured by the firm Leipziger 
Cementindustrie Dr. Gaspary &• Co., of Markranstiidt, near Leipzig, should, therefore, 
prove of interest to our readers. 

Intermittent mixers usually take the forin of trough mixers, i.e., machines which 
are provided with a trough, open at the top for the reception of the material; in the 
interior the mixing is effectetl by rigid or movable rotating inixing blades. These 
machines are fed in measured quantities, and, after having worked the material first in 
a dry and then in a wet state, the trough is emptied by tilting. 

367 



INDUSTRIAL NOTES. [CGNCI^I^ 

Fig. I shows a tiltinjj tr(>ut;h mixer which c.in be worked by hand nr power, and 
which is capable of mixintf 2 to 4 cubic metres an lioiir, acci>rdinij to size. The 
materials are moistened through a perforated pi|x-, which is fed from a water supply 
box above the tiltin}^ trough. 

Ihere are two kinds of coiitiiiuous mixers; first, those in which the material passes 




through without a stop, anti in which the mixer must be fed in measured quantities. 
Secondly, those in which the materials are measured oil automatically. 'I'he drum 
mixer, of which an illustration is shown in Fit;. 2, belongs to the first t\pL^ Mixing 
shovels are provided in the interic«- of the rotating tlrum to ensure the thorough 













NNEL-PLATE Mi: 



working through of the material ; these shovels are turned by the rotation of the drum. 
By means of the supply tank above the mixing drum, and a perforated pipe, connected 
thereto, and extending into the interior of the drum, the mass, which was mixed dry in 
the first section, is moistened. 'I'he out]iut of these mixers, which are built for 

36S 



E 



CONCRETE MIXERS. 



operation by hiiiwJ i>r power, and which arc cither movable or stationary, varic-. troni 
j to 5 cub. metres per hour. 

The funnel-plate mixers, in /•i.i,'. 3, are continuous mi.\ers which measure out the 
material automatically. The clitTerent materials are fed into funnel-shaped receivers 
which are o\Kn at the bottom, and below which there are rotating plates. By means 
i)f adjustable openings in the receiver the mass drops upon the projecting rims of the 
plates and is swept down into a mi.\ini,'- trout;h in which a mixing screw is working. 
The moisteninjj; of the mass is also elTected in this trough. 

.Ml these mi.vers, after once being adjusted, measure the raw materials auto- 
m.ilically ; they are to be recommended where reliable help cannot be obtained. Such 
a m.ichiiic worked bv hand turns out from i to \!, cub. metres per hour. When worked 
hv power thcv mix from 2 to 20 cub. metres an hour. 







k^' tvj/^ 




The universal mixer shown in Fig. 4 is a continuums one, which combines the 
advantages of the best mixers heretofore known. It can also be made for intermittent 
mixing, with a trough open at the top as shown in Fig. 5. The mixing is done by 
means of mixing blades which rotate with the drum. The direction of this rotation 
can be changed by merely switching a lever, which is one of the chief advantages of 
this system. The repeated change of direction of the blades causes a more complete 
mi.xture of the materials, and bv this means the mi.xer can also be more easily 
adapted to the existing motive power. It is easily seen that the power is considerably 
less when drums and mixing arms move in the same direction than when they go in 
opposite directions. The change in the direction of the rotation is also of great 
advantage for cleaning and emptying the mixing drum. .-Mso by repeatedly changing 
the rotation any stones, etc., which may have stuck fast between the walls of the drum 
and the blades can be removed immediatclv. 



36, 



INDUSTRIAL NOTES. 



[COCBETFJ 



It is absolutely necessary that mixing machines be adapted to the materials to be 
mixed, and they should be selected only after the output required and the power have 
been carefully considered. 







Fig. 5. Uni- 



For iNTERMr 



The Cementindustrie Dr. (iaspary &■ Co. are always pleased to allow anvone to 
ins|X'Ct the mixers in o|X"ration at their own f.'ictory, or to sjive the names of firms in this 
country where the mixers are in use, so that prospective purchasers may get the best 
information possible and may see the general etKciency of these machines and how 
thoroughlv tlie materials are mixed. 



CORRHSPOXDBNCE. 



CORRESPONDENCE. 

Under this heading tve wvlte correspondence. 



20 Victoria Street, London, S.W., 
April i8th, 1910. 
Regulations tor Reinforced Concrete. 

Sii;. I li.i\<- rtail willi iiiltrcst the arlicli- by Mr. William Dunn, 
l-'.K. l.H.A., which yiui have |)iiblish<'cl in your April nunilx-r concerning rej^ulations 
for reinforced concrete buildinj,'s in London. 

In your editorial notes on this article you evidently consider that Mr. Dunn is 
entirely ajjainst the adoption of regulations. 1 think, however, that this is not the 
ease, but that he merely wishes to emphasise the danger of over-regulations, and, in 
this res|x;ct, I am entirely at one with him. 

It is a matter of extreme importance to all specialist designers of reinforced 
concrete that there should be freedom to use it for walls and entire buildings in London 
and other large cities. Such regi lations as are necessary should have a certain 
amount of elasticity. 1 think that in this respect the authorities would be well advised 
in copying the spirit of the French rules, which are drafted out in such a manner as 
to leave a consi<leral)lp amount of scope to the skill of the designer, while at the same 
time safeguarding the public against any risks due to the fact th.il the concrete and 
the steel have been unduly stressed. 

I am of opinion that the new- regul.itions should state that the calculations of the 
resistance of the various members of the structure should be based upon the principles 
of the strength of materials, or upon i)rinciples affording at least the same guarantee 
of accuracy as those of the resistance of materials, and not upon empiric.d methods, 
which cannot be easily verified by the application of the usual well-known principles. 

The fact that there are no official regulations at present is certainly very detrimental 
to the progress of reinforced concrete, in that the public hesitate to use it without such 
standard rules. In certain cases it is ahnost hopeless to try to reconcile the require- 
ments of an <'Conomical scheme in reinforced concrete with the requirements of a 
district surveyor, who has omci.illy nothing at present to guid<? him for the verification 
of a proper design. 

.\s far as I have been able to ascertain, from conversations with the various firms 
of s()ecialist designers, the recommendations set forth in the Rei>ort of the Committee 
on Reinforced Concrete of the Royal Institute of British Architects would seem to give 
satisfaction to everyone concerned, and I think that with a few amendments the 
authorities could quite well base their regulations upon this report ; but it is essential 
that the rules should be capable of alteration, to keep pace with the advancement of 
invention and knowledge. 

Yours faithfully. 

Edmo.nd Coig.net, Ltd., 
(G. C. Workman, Managing Director). 
The Editor, Conckktf. .\nd Constki r tion \i. Ent.inf.kring. 



.April. if)io. 
London's Regulations for Reinforced Concrete. 

SiK, — The article du " Rci^ul.itii.nx for Reinforced Concrete Buildings in London," 
which Mr. William Dunn, F.R.I.B..\., contributed to your columns last month, was 
of great interest. Mr. Dunn, however, raised controversial points, and though he 
put his case clearly and argued forcibly and pointedlv as is his wont, it is unlikely that 
everyone will admit that he is altogether right. 

Mr. Dunn's complaint against building regulations becoming specifications is 
a just one, and the writer agrees that American by-laws run to excess in that 
direction, but where buildings are erected close together in towns there must be 
some su|)ervision in order to protect the public and to prevent the individual in- 
fringing upon the rigiits of others. Such n function can hardly be served by such 

G - 17 J 



CORRESPONDENCE. 



[CQNCBETE3 



a simple code of by-laws as that for which Mr. DLinn sighs. When architects 
and builders are all registered and educated in the mechanics of building, 
we may profitably discuss whether we can leave the individual w-ithout 
supervision by public authorities. The Joint Committee on Reinforced Concrete 
appointed by the Royal Institute of British Architects, in the drafting the reports of 
which Mr. Dunn has a large share, specially asked the authorities to make regulations 
for reinforced concrete construction, and Mr. Dunn, so far as the writer's knowledge 
goes, has never e.xpressed himself at variance with the rest of his Committee 
on the point until the London County Council sought to act on the suggestion. He 
ought to praise the London County Council for moving so quicklv after the report, and 
on securing the powers which the R.LB.A.'s Committee desired it to secure. The 
paragraphs in the Coinmittee's report referred to are as follows ; 

" The By-laws regulating buildirg in this country require external walls to be in brick, or stone, 
or concrete of certain specified thicknesses. In some places it is in the power of the local 
authorities to permit a reduced thickness of concrete when it is strengthened by metal : in other 
districts no such power has been retained. We are of opinion that all by-laws should be so altered 
as to expressly include reinforced concrete among the recognised forms of construction. 

" A section should be added to the by-laws declaring that when it is desired to erect buildings in 

reinforced concrete complete drawings, showing all details of construction and the sizes and positions 

of reinforcing bars, a specification of the materials to be used and proportions of the concrete, and 

the necessary calculations of strength based on the rules contained in this report, signed by the 

person or persons responsible for the design and execution of the work, shall be lodged with the 

local authority." 

Now surely, if all these details are lo be furnished the local authoritv should have 

some standard w'hereby to check them. .\nd it should be noted that the R.LB..\. 

Committee are evidently not in agreement with Mr. Dunn's opinion as expressed in 

his examination before the House of Commons Comtnittee on the Bill promoted bv 

the L.C.C., that the furnishing of details of the structural design would delav the 

erection of buildings in London and result in loss of income and increased expense, 

confusion and annoyance to building owners, to an entirely unnecessary degree. 

It is generally admitted that the London Building .\ct of i8q4 was cumbersome, 
often ineffective and unnecessarily oppressive, but this is chiefly attributable to its form, 
the reg'ulations being fixed hard and fast by .Act of Parliament, which had to be 
enforced, and could not be altered or amended without going to Parliament again. 
The later Acts have had saving clauses which give power to the London County 
Council to alter and amend regulations from time to time, but this, it has been 
thought, would give power to the officers of the London County Council, without 
subjecting them to supervision and power of appeal against possible arbitrary use of 
that power. The desired control is now secured by providing that regulations shall be 
submitted in draft to the technical societies and finally approved by the Local Govern- 
ment Board, and by having the Tribunal of .\ppeal to give a reasonable interpretation 
in case of dispute. Mr. Dunn sandwiches his argTjment with a nuinber of trite remarks 
that will not be disputed, but they do not always apply. How such regulations as 
those recently adopted for steel-frame buildings can legitimately be said to remove 
the responsibility from the individual it is difficult to see. It is rather surprising to 
have Air. Dunn advocating the policv of laisser jaire in connection with regulations 
for reinforced concrete, for he is the consulting architect whom H.M. Office of Works 
gets to examine and advise upon designs submitted in competition by reinforced 
concrete specialist firms, and these designs have to be prepared in accordance with 
the report of the Joint Committee appointed by the Royal Institute of British .Architects, 
which goes into considerable detail. 

There is a great temptation in these times of keen competition for contractors 
to take risks and reduce factors of safety. Though no serious accidents have fortunately 
occurred in London, there have been some elsewhere, and, indeed, there have been 
failures in London which have given proof that supervision is hjjjhlv desirable. Of 
course, it is admittedlv impossible for public officers to keep a constant supervision 
over materials and workmanship; but it is just as well to see that the working drawings 
are correct, and surprise visits can be made to jobs to see that the arrangements are 
such as to conduce to work being properly carried out. The district surveyors of 
London do excellent work at present in other directions with just as many imaginative 
disadvantages as are put forward by Mr. Dunn. 
.?7' 



\j. (lONSTPHlTIONALl 



CORRHSI'ONDHXCE. 



riic vorv f;icl of lb 



Ihc <lc.i,nlc-.d |K„nls ihal Air. Dunn raises to illustrate his remarks should be e-.silv 
n,et ,u.w that tlu- rtnes are to be op.-n to tl,e cri.icisn, of professional scieeTherJe 
vanous fun.lan.ental pnnciples of applic.l ,necha.,ics and sonte general g'ement.moni 
engwK-ers as o reasonable factors of safet>- to provide on the ul n ue renj s of 
materials, and these can be the subject of re-ul'ilions '[-h.-r^ "luma e .strcntjths ol 
hivestigation in connection with reinforced ccm cr tc heorv • nd or^ctie^ '"''""''' 

\ ours faithfullv, 
The Kditor. CoMKKiH AM, CoNsiiaritoNM E ^"'" ''^'•'^'^'^'<- 



Vl-.KHIN( 



5 \ ictoria Street, S.W., 
T- . April j;th, loio. 

Tests on Columns. :> • i "■ 

u)o,. An account of im s .t S-n h ^^^^l^^X' .:^?'{r'-''''''T'''' ^''"^ 

forced Concrete" (Constable X- C^7 ' ) niM^ .S- 1 "^ Dunn s work, " Rein- 

IHU verbatin, .abstract fron, this volutne ' ^ " """ '•''"^"'^' '^ ■' I"''"'''' 

In the full reports of his experiments in tlu- R I B \ l,,uriv,I M,- r^ i 

quot.H.on will sho\\; this conclusively «-onsicHre ."spiral. The followmg 

supervs.on; tn fact, under such conditions .as would aZt ,. woH ; ' ,^ '";* 
a concrete s|X'cialist. " '' • ^ '" ' """'' ''X 

bein?"i^hUvt::f than ^TT:;:!^ Y ''"'\ "T" ""■ ^"""^'■" "f "- io"Ki.udinals 
recotnmende I M ( on\id re i, Id A"' '-^ "■' ."""'-■''"^■' '''^''^ '' '^^ nnn.imum 
the spiral w uK nl:i'"u.1rcn^.Z^^ '"''' ^'^ ''"■'"''>' '"™ '" ^^f^^" '^•"t'""' 

the ainount o pir .r „ rin 7 1: ^ ^' "? '"'^''V'"' I'""' ■^''"- ^""" ^^'-"^^ 'h='' h-->d 

-o".^^ s^E^stfii^^s^ssj'^u.s-^- 
f.m be consMere™,; d" finL V ; ,fv J ° ' ""'""f "Peri'"e,..s. .,nd „,av ,kere- 

The Considere Construction Company 
The Editor, Coxc.ht. .xo Coxs.«.cnox.. Excxn^l^t^" '"• '^^ ''~^'^' ^'''"^'^•^^• 

super..™... We are A to reco^/^-j^^L^XtT'^r i;;^hr2,?^ttt;^" E^.T'i^^li^;^'^!]^ 

373 



MEMORANDA. 



ICQNCBETFJ 




MEMORANDA, 



LaJ 



Concrete Institute— Visit to Paris.— On Friday, April Sth, the deputation visited 
the Church ul St. Jean de Montmartre, an extremely interesting- structure erected in 
i.Stjb on the Cottancia system. It is particularly noticeable for the lightness of the 
construction, every endeavour havinsr been made, seemingly, to reduce the dead weight 
of the building, and yet provide ample strength. Then a visit was paid to the Canal 
St. Martin to inspect the reinforced concrete roofing over a portion of the same. This 
work, begun at the end of 1906 and completed in fifteen months, consists of a continuous 
three-hinged arched covering on the Boussiron system, filled on top with earth which 
is laid out as a public garden with trees and makes it into a magnificent boulevard. 
The novelty in the construction of this arch is that the hinges are not independent 
articulations, but merely consist of reductions of the section of the arch, at which 
points bars are embedded sufficient in area to take the thrust, and simply covered with 
concrete to protect them against corrosion but in no wise to .augment their resistance 
to compression. In the afternoon the deputation visited a reinforced concrete tank at 
Gennevilliers, an underground gallery at .\rgenteuil, and a culvert at .\cheres, in 
which were large pressure pipes, on the Bonna system, conveying sewage, that have 
been in use for sixteen years, all connected with the sewerage and sewage disposal 
works of Paris. 

On Saturday .M. Ilennebique's house, No. i Rue Danton, Paris, and his country 
house at Bourg la Reine were visited. The first is a tall building containing a flat 
for M. Ilennebique's personal use and offices used by staff of the Hennebique firm. 
The country house is a remarkable structure of reinforced concrete, which shows some 
of the possibilities of the system of construction. On the same day an elevated water 
tank, built in iSqq at Billancourt, and bridges, tunnels, cantilevers, platforms, and 
buildings in reinforced concrete on the Paris to .\uteuil Railway were inspected. These 
w-ere all on the Hennebique system. 

Concrete in Mining Construction. — Recent mine disasters have directed attention 
to the desirability of using fireproof material in mining construction, and in a few 
instances some interesting and satisfactory pieces of work have been done with 
concrete. 

Perhaps the most unusual of these was in the construction of the Kidder shaft 
of the Cleveland ClilTs Iron Company, near Princeton, Michigan. The pjroblem was 
to reach a ledge lying about 100 ft. below the surface, of which the covering consisted 
principallv of quicksand so thoroughly saturated with water as to make ordinary' shaft- 
sinking imp>ossible. It was determined to follow what may be called tunnel methods. 
A reinforced concrete shaft was erected on the surface to a height of 15 ft., and 
excavation was begun from the interior with a clamshell dredge operating through 
several sections of steel dredging cylinder sunk in the centre of the shaft. As the 
material was removed the shaft followed the course of the excavation by its own weight, 
moving along like a tunnel shield but under natural power. .As the shaft settled it 
was built upon at the top and the building kept pace with the sinking until a depth of 
87 ft. was reached, when a stratum of hard clay was encountered which could not be 
handled with the dredge. From this point the dredging shaft with slight alterations 

374 



l&^S?j;i£^'.lJ.^^J MEMORANDA. 

was tc|iii|ipc<l for compressed air o[x;ratioji, and ihc excavation continued hv caissons 
111 the necessary depth of i 13 ft. The shaft is id ft. in diameter inside, and at the 
joint with the ledj.;e the walls .arc 3 ft. (> in. in thickness, gradually increasing^ from 
2 ft. in thickness at the upper end. 

Near C'alifornin, Pa., the .Monongahel.i River Consolidated Coal and Coke Company 
has made extensive improvements in lining^ the shafts of a mine throuf^fhout with 
concrete. A part of (he work is a double-track section of the shaft 15 ft. wide in the 
clear and S ft. in heii,'^ht lo the centre of the arch. The two sh.ifts, which h;ive :i 
conibinwl lenf^th of ^25 ft., are lined throughout with concrete varyini; from 1 ft. to 
J ft. in thickness. 

The H. C. Frick Coal .and Coke Company, Pittsburg, has built two concrete shafts, 
one for working and the other for ventil.ition, ;it one of its mines in Peimsylvania. 
Both are elliptical in sha|)e, one being 13 ft. by 28 ft., and the other 14 ft. by 3J ft. 
One shaft was begun by e.\cavation by drill and blast to a depth of 50 ft., the dimensions 
being locatcKl by the use of a tenipl.ite with plumb bobs susjiended from it. The 
excavation was kept 12 in. outside the lines of the ("mished shaft. .\t this depth 
collapsible forms were built and the concrete work completed to the full depth. While 
this work was in progress the excavation of the other sh.ift was completixl and the 
concrete placed. The working force then returnetl to the first shaft and the two were 
carritnl on simultaneouslv to a depth of 650 ft. The excavation was nearly all through 
solid rwk with the exception of about iS ft. at the surf.ace. The coping of each shaft 
for this distance through the surface soil was made about 5 ft. thick, and serves as 
.1 foundation for the piunping .and hoisting machinery, while in the rest of the shaft 
the thickness varies from 12 in. to 24 in., the latter thickness being required in some 
of the softer strat;i of fire-clay and other materials. Though the cost of concrete 
construction was considerably higher than wood construction would have been, the 
size of the coal vein was supposed to l)e such as to warrant the extra expense, the 
view being that it would Im> counterbalanced in a period of years by lower maintenance 
charges. — The Ti»ics Eiigineeriiif; Siipplenicitt. 

Tests of Portland Cement.— Dr. W. Burchartz reports the results of tests of 
100 Oerinan Portl.uul cenunts and of 20 Belgian n.ilural cements, carried out in the 
Testing Station at (iross-Lichtcrfeld during the past year. Thve quality is found tr* 
varv within comparativelv narrow limits, as is shown by a number of frequency curves 
included in the report. The average results of the Portland cements are : .\p]Xirent 
density I'lo — 115; s]X'cific gravity 305 — 315; loss on ignition under 4 per cent. 
Residue on goo sieve (British 76) 0--1 per cent., on 5,000 sieve (British iSo) 15- 20 per 
cent. The tensile tests on mortar after 28 days gave very closely 25 kilog. jx-r sq. cm., 
and the com]>ressive tests 200 — 250 kilog. ixr sq. cm. (35!) ajid 2,820 — 3,560 lb. \xr sq. 
in. respectively). Practically all the samples \vithsto6d the boiling test. 

On the other hand, the Belgian natural cements have a lower specific gravity 
(29 — 3'o) and commonly fail in the boiling test, although showing no unsoundness in 
a cold water test. The tensile and compressive tests are always lower, being usually 
16 — 19 kilog. per sq. cm. am! ii(> ido kilog. per sq. cm. respectively for 28-day inortar 
(228 — 270 and 1,650- 2,2So lb. per sq. in). They are ground to the same fineness as the 
Portland cements. 

The chem^ical analyses show that the proportion of lime in German Portland 
c-enients averages 62"99 f)er cent., the maximum observed being 68' 12 and the minimum 
56'88. The .■iver.age pru]K>rtion of silica is 2o'S7. and of alumina and ferric oxide 
lo'bi per cent. 

Gravel v. Limestone In Concrete .4;g'^re;fafe. Comparing the relative value of 
w-ashed gravel and crushed limestone as a factor in concrete aggregate, Mr. .Arthur B. 
Hewson presented some interesting figures and facts before a recent meeting of the 
-Architects' Business .Association of Chicago. He contended that any given quantities 
of cement, sand, and gravel mixed in the usual proportions, such as i : 2 : 4 or 1:3:6, 
will make at least 7^ per cent, more concrete than equal quantities of cement, sand, 
and limestone; also that, at prevailing prices for gravel and stone, the former is 
decidedly the more economical, at the same time showing greater strength, efficiency, 
and fire-resistance. The explanation of the greater bulk of gravel concrete, said Mr. 
Hewson, is that gravel, on account of the rounded shape of its particles, averages 75 
l>er cent, less in voids than crushed stone. When you mix concrete i : 2 : 4 or 1:3:6 

37i 



MEMORANDA. ICQNCBETE ] 

you have 50 per cent, of sand to fill the voids in the coarse ag-gregate. If the voids ir. 
crushed stone absorb 95 per cent, of the sand and the voids in the gravel only 80 per 
cent., it naturally follows that 15 per cent, more of the sand appears in the gravel 
concrete, thereby increasing its bulk 75 i>er cent. Practically all authorities agree that 
the voids in the averaged washed gravel are 40 per cenl. and in the average crushed 
stone 47'4 jx'r cent. Continuing, Mr. Hewson said : It is agreed that the strongest 
concrete is that in ^Vhich there is just sufficient sand to fill the voids in the coarse 
aggregate plus a small percentage to cover inequality in mixing, with the same 
conditions obtaining between the sand and cement. When you add more sand than 
this you weaken \our concrete. Does it not follow that, if gravel concrete excels 
limestone when compared in identical proportions, it would still further excel in com- 
parisons where the sand is in the same proportion to the voids in both materials? For 
illustration, would not a lA : 3 : 7 gravel concrete excel a 1:2:4 limestone concrete? 
Would it not be proportionately rich in cement? Would it not give an equal bulk of 
concrete and a greater strength efficiency with less sand and less cement? Furthei*- 
more, if a 1:2:4 limestone mixture produces a smooth finish, will not a I5 :-3 : 7 
gravel concrete do the same, since the proportion of mortar to the voids is identical in 
both cases? In confined spaces, where the intervals between the reinforcing bars are 
small or the concrete must be forced through wire mesh, a denser and, therefore, 
stronger concrete can bo obtained with gravel. The rounded particles work into place 
more readilv and lie snug to the steel. There are few jagged edges to catch on the 
steel or on companion particles, forming pockets which reduce the strength and damage 
the ap]X>arance of the surfaces. Gravel concrete, pro]X'rly proportioned, will produce 
water-tig'ht walls, where limestone will fail under the same conditions. This is also 
due to the lesser proportion of voids and the closer association of the particles. With 
regard to the fire resistance of gravel concrete. Bulletin No. 370 of the U.S. Geological 
Survey shows its sujierioritv over limestone. The limestone is badly damaged by 
calcination. This Indletin also shows that fireproofing tile, sand-lime brick, and 
practic.dlv everv other m.iterial except solid concrete, are useless for fireproofing. 

Reinforced Concrete Paving Joints. — .\mong the first concrete pavements laid 
in tlie I'niied St.ite-., acconling ti> tlie Surveyor, were tTiose put down at Bellefontaine, 
Ohio, alioLit seventien }c,ir- agn, and after such a length of service they are still in 
good condition, except for wear at the joints. Other similar well-constructed pave- 
ments in different cities show the same weakness. To overcome it Mr. R. D. Baker, 
of Detroit, Michigan, last jear originated and used an "armoured expansion joint." 
The reinforcement consists of a steel plate at the edge of expansion joints wherever 
necessary to provide for expansion and contraction. Where such a joint is to be made 
each edge is protected first by a steel plate tV in- wide. Between the two edges thus 
protected is placed a board. When the board is removed the cavity left by its removal 
is filled in with pro]ier paving pitch or other suitable material. Some of the pavements 
thus constructed in Detroit have been subject to severe tests in the way of heavy 
traffic, and, it is stated, seem jjerfectly s.-itisfactory. The added cost is said to be little 
compared to the Listing improvement in wear. 

Urban District of Wood Green. — Erection of Public Baths. —The Council 
invite schemes and tenders for a reinforced concrete swimming tank, heating of the 
bath, private baths, etc., and steel roof trusses and sliding lantern over same, from 
firms who are respectively specialists in such work. 

Forms of tender, preliminary specifications, and copies of plans may be obtained 
at my office on or after 22nd instant, on payment of a cash deposit of ;£r3 for each set, 
which will be returned on receipt of a houd-fidc tender and drawing. 

The general conditions, subject to which the contracts will be submitted, and all 
further information may (on the production of my receipt for the deposit) be inspected 
and obtained from the .\rchitect, Mr. Harold Burgess, Capel House, 62 New Broad 
Street, E.C., between the hours of 3 and 5 p.m. 

Sealed tenders (upon the forms supplied only) addressed to me, and enclosed in the 
endorsed envelope supplied, mtist be delivered to me at my office not later than 4 p.m. 
on Wednesday, May nth. 

The contractor will be required to pay the wag'es and observe the hours of labour 
in accordance with the scheme, a cop\' of which will be annexed to the contract. By 

376 



MHMORAXDA. 



order ol ihi- iDuncil, Win. P. I l.irdiiif,'-, ("lork of t]ic Coiincil, Town H.ill, W'ikicI (irrcn, 
.\|iiil 14II1, i()io. 

The "Licentiate RJ.B.A." — 'l'\n- Royal Inslitiitc of Hrilish Arcliilrcls have 
issiirJ llu- following; Iclicr lo tin- Prt-sidcnm of lli<- AHit-d Societies on the subject of the 
new ■' Liiiniiaic " class wliich, under the new Charier, is to be formed in connecliiHi 
«itli ihe Insiiiuir. Tile letter is as follows : 

Dkau Sik. W I h.ivc the honour lo invilc ihf atli.'nli»n of your Soi iciy lo an importunt 
lievflopmeiil in the c onslilulion of the Koyal Inslilute of liritish Arrhilfits which has lately 
been sanctioned by llu' j;rant of a SiippUmenlal Charier and new bydaws by His Majesty the 
KinH and the I'rivy t'oiineil. 

A new class of members, having the < harlercd right lo the designation of Licentiates of 
llic R.I.H.A., has been created. This class is open lo all prai lising archileds of good standing 
who have attained the age of 30 years and cither {a) have been engaged as principals for at 
least five successive years in the practice of architcclure, or (*) have been engaged for at least 
ten successive years in the practice or the study of architecture. 

Candidates for this class are not retjuireil to i)ass an examination or to submit lo election 
by the general body, but must satisfy the Council of the Royal Institute that ihey are fit and 
pro|)er persons to be admitted lo this class. 

Under lite trovisious of the Siitplemeiitary Charier of iQoS candidates for the class of 
Licentiates will only be admitted during the tweh'e months from A/arch Jjrd, iQio, to 
March 23rd, IQtI. 

Under His Majesty's Charter any Licentiate who is eligible as a Fellow may at any time 
before December 31st, lyjo, be admitleil for nomination lo the class of I'ellows when he has 
passed an e.\amination lo be prescribed by the Council. 

Licentiates will be rcipiired to make an annual payment of one guinea to the Royal Insti- 
tute, and for this they will be entitled (il to use the afB.\ Licentiate R.I.H.A., (a) to receive the 
ft'urnal, the Kalendar, ami other publications of the Royal Institute, (3I to use the Institute 
premises, and (4), subject lo the Charier and bylaws, to attend the meetings of the Royal 
lastitute. 

In view of the necessity of closer organisation of the members of the architectural pro- 
fession throughout the Lmpire, both for the advancement of the art of architecture anfl for 
the promotion of the interests of the profession by means of Parliamentary or other action, 
it is highly desirable that a knowledge of this new means of becbming associated with the 
work of the Ro\'al Institute should be spread as wiilels' as possible among those architects who 
are at present outside its walls. 

Any action which may be taken in the future to secure a higher standard of professional 
attainment and a greater security for properly qualified architects can only be successful if it 
is based upon the supi)ort of a substantial majority of the practising architects of the Kmpire, 
and the Council of the Royal Institute hope that your Society will do all in its power to assist 
the efforts that are now being made to obtain this support. 

We have pleasure in sending you herewith a packet of nomination papers for Licentiates, 
and we shall be glad if you will take an early opportunity of making an official announcement 
and of taking efTeclive steps by sending by post to all the architects in your province a notice 
of the creation of this class, drawing special attention to the fact that it is only open for twelve 
months, and informing them that the above papers arc in your hands and may be obtained on 
application at the offices of your Society. 

We feel that it is the duty of the Institute and its allied Societies to get into touch with all 
architects in the l-".mi)ire, and we are sure we ma\- count on your zealous personal assistance to 
this en.l. 

TRADE NOTICES, CATALOGUES. ETC. 

The British Ceresit Waterproofing Co., Ltd.. Caxton House, Westminster, have 
sent VIS an illustrated bix>klet settint; forth the advantages of their preparation, which 
they claim is the most simple, efficient, and economical waterproofing^ on the market. 
Ceresit is a cream-white paste which dissolves immediately in the water with which 
cement mortar or concrete is to be mixed. .\ coating of cement mortar waterproofed 
ivith Ceresit has been found completely successful in rcnderintj structures of any 
material, brick, stone, concrete or tile, thoroughly waterproof and damp-proof. Where 
new structures are to be built of concrete, thev may be made waterproof throughout, 
without necessity for any exti a coating, by using Ceresit in the water with which the 
concrete is mixed. No s])ecial mixing or expert help is required. Ceresit has been 
used by the State Covernment R.iilw.-ivs of dermanv, France. Russia and .\ustria ; at 

377 




CONCKETEX 



coNisTRumoNAi::; 

£T>IGITME,E,RIlSfG 




V/^ 



^^^'fS^IS^ESaE FOU SEWERS, 
SS£r]5J?SEg)« BETTER CIJLVE]IT5,CQNDUITS, 

FliNISn ON THE CONCRETE. ARCHES, ROOFS E"^ 



ILLUSTRATIONS SHOW CENTERS 
IN USE ON COMBINED BRICK AND 
CONCRETE CULVERT, FOR THE 
NORTH-EASTERN RAILWAY CO., 
AT BLYTH, NORTHUMBERLAND. 




THE CONTRACTOR FOR THE WORK WAS 
MR T TELFORD GIBR 



di 



THE BRITISH 
STEEL IS^ 
PILING 
COMPANY,Ba 



SfLMTEl^sT LOiHDOiH.B.C 



Ple3.S€ mention this Journal when writing. 



rCONCBE TEJ 



MItMORAXDA. 



ttn- Kaiser's Palace, I'osen ; Diisseldorf City Hospitals; Hotel Eden, Zurich; Sterrebeck 
<"aslle, lkli,niiin ; (it-nnan Government dams, and reinforced concrete cisterns for the 
r.S. GdvernmeMl, l''l<iri<la, etc., etc. 

The British FIbm-Cement Syndicate, Norfolk House, Laurence Pountney Hill, 
K.C, call our attention to a report of a fire at Linion, Costa Rica, taken from the 
<"osta Rican journal. La lnjormacio», in which it is stated that, in the centre of one of 
the l)k>cks which were burnt down, one sinj^jle house, although surrounded by flames on 
all sides, remaimd standing; without havintj sufTered any damage. This house, in the 
construction of which " Kibro-Cenient " was used, is said to have " trrumphantly 
emerged from a severe test, and proved to be an ideal building material at a port which 
is always threatened by fires." 

The British Improved Construction Co., Ltd., 47 Victoria .Street, S.W., gave 

l.isl monlh, ;il ihcir I'utli.iin works, a most interesting demonstration of the Jagger 
svstem of construction in llie manufacture of concrete sewer pii)es, railway slee|5ers, 
telegraph poles, etc. .\ s|X"cial feature of this system consists in the vibratory and 
oscillatorx' process to which the moulds attached to the jagger table when being filled 
with concrete are subjected. This vibration, combined with a sudden arresting or 
rocking " cross " motion, has the elTect of producing a rapid solidification of the 
l)articles before the initial set of the cement occurs. It is claimed that the greatest 
densitv and homogeneity is thus obtained, the aggregates being bound so closely 
together that air holes and cavities are entirely eliminated. The Company guarantee 
for all their concrete an absolutely uniform standard of strength, capable of calculation 
.and variation in respect to the strength of the aggregates and the volume of cement 
used. With reference to the reinforced concrete sleepers made by the Jagger process, 
these are stated to be almost indestructible and everlasting, of a standardised strength 
and uniform finish, densitv and te.\lure throughout, completely immune from hair 
cracks in the surf.acc, and capable of construction at a very moderate cost. They have 
l)c<'n use<i b\ the S. \'.. i\. ('. Railwav. and are also being' tried bv the fireal Northern 
Railway. 

Builders' and Contractors' Plant, Ltd., 17 \'ictoria .Street, .S.W. (whose former 
title was (ieneral Constructions .Machinery Sui)i)ly, Ltd.'), ha\'e brought out a useful 
catalogue of their " Roll " concrete mixers, sand .and gravel washers, etc. Numerous 
illustrations are given, together with descriptions and instructions as to methrxis of 
wiirking both hand and power machines, .\mong the many important contracts on 
which the " Roll " mixers were used, the following may lie mentioned :.\ntwerp Fortifica- 
tion Works, Brussels- Antwerp C.m.il, Amsterdam Harbour Works, \'enice Fortification 
Works, etc. 

The Trussed Concrete Steel Co., Ltd , C.ixton House, Westminster, have 
lirought out an illustrated pamphlet and price list res]X»cting their " Hy-Rib " steel 
lathing for partitions, ceilings, walls, roofs, sewers, etc. Hy-Rib consists of a steel lath 
surface stiffened by rigid high ribs, and when used in concrete floors and walls no 
centering is required, the ribs giving sulTicient strength and rigidity, while in walls and 
partitions it does away with the use of studs. The lath surface is str.aight and true, 
and the expansion is such as to produce a perfect clinch with a minimum amount of 
I>laster. Hy-Rib is used in construction work of every kind, floors, roofs, walls, par- 
titions, ceilings, and furring. Curved Hy-Rib (bent by the special rolls with which the 
firm's shops are equip])ed) is used for arched floors, culverts, conduits, sewers, silos, 
tanks and reservoirs. The booklet illustrates and indicates the general applications of 
the materi.d. but detailed suggestions for any particular work will be furnished by the 
Conipanv. 

The Leeds Oil & Grease Co., of Chad wick Street, Tweeds, have sent us some 
particulars of their Concrete .Mould Oil, which .should be of general interest. This 
preparation is, we understand, found to prevent the concrete sticking to the moulds in 
shuttering concrete, and also to protect the timber from the action of the wet concrete, 
thus lessening the possibility- of its becoming warped or twisted, as might otherwise 
be the case. The oil is applied to the mould or shutter with a brush, and should, 
if possible, be allowed to dry somewhat before the concrete is filled in. Sf)ecial 
mention is made ot the low price of this Concrete Mould Oil, as also of the fact 

.^"9 



MEMORANDA. [CONCBETEJ 

that it has been used by the Admiralty, by leading railway coTiii).iiiie>, public 
works contractors, etc. Free samples are supplied upon request. 

Davis Bros., or hfi Deanss^ate, Manchester, have sent us a booklet descriptive of 
the " .\pix>rtioner " mixin.u: machine, which they have just put on the market. This is 
an aijparatus for automatically mi.xing^ dry materials of any description, cement, paints, 
chemicals, etc., and is claimed to produce a uniform composition at considerably less 
cost, power and trouble than has hitherto been possible. .V standard machine is made 
with two 4-in. screws to mix two ingredients, and \\ ill deal with 15 cwt. per hour, more 
or less, according to the character and proi»rtion of the materials. Machines will also 
be designed for sj>ecial requirements to mix up to eight separate ingredients, and of 
capacities ranging from 5 cwt. to 20 tons per hour. 

The British Uralite Co. (1908). l-td.—W'e are advised that Mr. J. J. S. 
Davidson has resigned the man.-'.ging directorship of the British Uralite Co., Ltd., of 
London and Higham, as, owing to his other engagements, he is unable to continue to 
give the close personal attention that the interests of the Companv demand. .Mr. 
Davidson is not severing his connection with the Company entirely, as he will continue 
to act as a director. Under his management the Company has been put on a sound 
financial basis; the factory has been reorganised, new markets have been developed for 
Uralite at pavable prices, and the manufacture of .\sljestone has been initiated to 
com|>ete with the cheap Continental materials. 

Mr. Arthur Koppel, 2- Clement's Lane, London, E.C., maker of concrete mixers, 
railway pl.int and installations, etc., informs us that, having amalgamated with the 
firm of Orenstein S: Roppel, the full title of the firm will in future be Orenstein & 
Kopi^el — .\rthur Koppel (.\malgamatedl. 

CONTRACTS. 
Messrs. D. G. Somervllle & Co., iiO \ictoria Street, S.\^'., have the following 
contracts in hand: Higham-Hellesdon Bridge for Norwich Corporation; Mendham 
Bridge for Norfolk and Suffolk County Council; Bosmere Bridge for Suffolk County 
Council; Lea Bridge for Benskin's Brewery; wharf at Portslade for J. E. Butt & Sons; 
new printing works at Brunswick Street, Blackfriars ; starch factory at -Ayr; lamp 
factory at Southfields; retaining walls at Mappin & Webb's, Queen Victoria Street, 
E.C., and R. Clay & Sons, Ltd., Blackfriars; new house for George Edwardes, Mary- 
lebone ; nurses' home at Norwich; new schools for Kent Education Committee, 
Sheerness ; building. High Street, Kensington; rinks at Maida ^"ale and Plymouth; 
water tower, Leicester; building, Finchley. 

-Messrs. Stuart's Granolithic Co., Ltd., of 4 Fenchurch Street, E.C., inform us 
that orders have been placed with them for reinforced concrete structures during the 
last montli : Two more factories at Hayes, .Middlesex; extensions to Maltina Bakeries, 
Blackfriars; new block at the Royal Hospital, Sheflield — to be called the Eldon Block; 
University Liverpool, block of buildings for the Students' Union ; reservoir at Bury, 
Lanes; silos for cotton seed, Stoneferr\' ; silos for grain at Barn,' Dock; schools at 
Rossall, Fleetwood. 



CONCRETE 

AND 

CONSTRUCTIONAL ENGINEERING 



\olunie \'. Xu. London, Jink, 1910. 

EDITORIAL NOTES. 



SPECIAL USES FOR REINFORCED CONCRETE. 

WHILST the progress made throughout the British Empire in the appli- 
cation of reinforced concrete to structures both above and below ground 
has been satisfactory, and a yet more rapid development is in sight, 
owing to the fact that the technical professions concerned have a better under- 
standing of the material than heretofore, we regret to observe that reinforced 
concrete is not yet being used to that e.vtent that we should exp>ect for what 
we would term minor purposes. Abroad, piarticularly in Germany. Italy, and 
the United States, the progress in this direction has been vers' rapid, and the 
economies thereby obtainable are well appreciated not only amongst the technical 
professions, but by the public authorities, and what is even more important, 
by the " man in the street." 

The reinforced concrete fence post, railway sleeper, telegraph pole, 
and electric light standard, etc., are notable and conspiAious e.xamples of the 
practicability and economy of the new material. Reinforced concrete drain- 
pipes, water conduits, tanks, and cisterns are becoming as common as their 
predecessors constructed either of clay or metal. 

For the everyday uses of the farm, estate, and other country purposes 
generally the development has been most remarkable, for where\-er a suitable 
aggregate can be found, and where Portland cement is within easy reach, the 
necessary" metal reinforcements seem to be forthcoming, crude as they may 
occasionally be, but the results are most useful. Capital expenditure is saved 
and maintenance expenditure reduced to a minimum. 

We have from time to time published numerous examples of the application 
of reinforced concrete to these many minor and specialist uses, and, as far as 
farms and estates are concerned, we ha\e. as a rule, selected examples from the 
United States, where the development in this particular direction is the most 
extensive. We would most strongly recommend the immediate and careful 
study of the subject to aU concerned ; and here we would specially point to 
those in authority with our great corporations, railway and carr\"ing 
companies, and o\m estate and agricultiu"al concerns. 

There cannot be the slightest doubt, that for the majority of the purposes 
named the advantages of using reinforced concrete quite outweigh those of 
materials such as metal and timber. Economy is a matter of the utmost impor- 
tance at the moment, both as far as capital expenditure and maintenance are 

3?i 



STANDARD NOTATION. ICQNCBETEJ 

concerned, and one way of effecting substantial economies is to follow the example 
set in the United States, Italy, and Germany, by applying reinforced concrete 
for those numerous minor purposes to which we here refer. 

STANDARD NOTATION. 

On looking through the recent papers and reports presented at this year's 
meeting of the Cement Users' Association of the United States, as well as of 
several other societies interested in reinforced 'concrete, we have been struck 
by the fact that the proposals made at the meeting of the International 
Commission on Reinforced Concrete, held last autumn at Copenhagen, did 
not appear to be receiving that attention which they merit, and this regardless 
of the fact that amongst those present were Professor Talbot and Mr. Humphreys. 

The latter gentleman, it may be remembered, is the President of the Cement 
Users' Association for the year, and also the secretary of the American Joint 
Committee on Reinforced Concrete, while Professor Talbot has all that weight 
which experience and the highest standing in his profession have given to him. not 
only in the United States but also in Europe. 

It would, indeed, be regrettable with the impending issue of numerous 
reports in the United States, and we believe also the publication of several official 
pocket-books on the subject of reinforced concrete, if some immediate effort were 
not made to assimilate the notations of the United States of America and those 
suggested for Great Britain. 

We would put it to those interested, both on this side and in the United 
States, that the matter is now becoming one of urgency, and energetic and prompt 
interchange of views is essential if any good is to be done. We hold that if the 
present opportunity is missed by undue procrastination it may be irretrievably 
lost, for once given the publication of a large number of reports and pocket- 
books in the United States, aU adopting an international notation different from 
that of Great Britain and its Colonies, it is unlikely that as time goes on there will 
be anj' tendency on the part of our American cousins to make a change, whilst 
at the present moment there is still an opportunity for getting things into line. 

WATERPROOFING OF CONCRETE. 

A CONSIDER.ABLE amount has been written during the last two years on the 
various forms of waterproofing concrete, and the more important contributions 
presented on the subject have been reproduced in these columns. An industry 
is now gradually growing up in waterproofing compounds, and we wish to draw 
the attention of those interested to this very useful departure in concrete practice. 
The merits of the various compounds are well deserving of examination. 
Some of them lend themselves to the work in a general way, others have special 
advantages for meeting special conditions. The subject is, of course, compara- 
tively new, and the experience obtained only extends for a limited number of 
years, but with the high development of chemistry to-day, the careful methods of 
testing, and the painstaking way in which the industries concerned prepare 
their products, we have every confidence that we are on the high road to the 
genei-al adoption of waterproofing compounds in everyday structural practice, 
and we welcome what we co,,sider to be a most useful innovation. 



RHTAIMNG WALLS. 






AW#i^>7'l .-^ RETAINING WALLS 

W% ~m ' V^WS^^If '^^ Hi:.\KV ADAMS, M ImiCE. 



I0;r^7 



!P;prfn^~'"' 



-rFSn-r^^^-^rr^^^rt^ 




- AS bcco'ni: d most importjnl question 'Where deep reljining ivjlts jre 

i(it-J ;.*J v: .*>' p-v;rt--;>, jnJ //it-fc" (5 no t/ou^/ //la^ with the advent of reinforced concrete there 
<iulll be a very considerable saving of space where structures of this description are 
concerned. 

The Interesting contribution presented below from the pen of Professor Henry Adams 
gives useful examples of work of this description. — ED, 



Up to about the year i860, retaining walls were generally constructed of brick 
or stone masonry in mass, of which Fig. i (Plate I.) is typical, but durinf,' the 
next ten years various modifications were made to reduce the quantity by a more 
scientific distribution of the material — e.g., by arching over counterforts in 
stages, by heavy buttresses with vertical arches between, etc. About 1870, mass 
concrete was commonly used for retaining walls, relying for stability upon its 
weight, the centre of gravity being kept as far back as possible as in the case of the 
earlier brick and masonry walls. Fig. 2 (Plate I.) shows a concrete wall with 
brick parapet, constructed about 1870, at Mildmay Park Station on the Xorth 
London Railway. Fig. 3 (Plate I.) shows a heavy concrete retaining wall built to 
sustain a surcharge. Fig. 4 (Plate I.) shows a lighter wall with batter front and 
hack. Fig. 5 (Plate I.) shows the retaining wall at Messrs. Cockerell & Co.'s 
Wharf. Blackfriars. Many concrete retaining walls followed these early ones, 
and, in course of time, certain difficulties and defects became apparent. 

In order to prevent unsightly irregular cracks, it was found necessary to 
make a vertical joint about every 60 ft. in heavy walls and 30 ft. in light walls 
to eliminate the stresses due to changes of temperature. In some cases the 
joints were plain vertical faces from front to back, and in others, a vertical groove 
and tongue about 12 in. wide were formed in the abutting faces of the joint. 
With reference to this matter, Thomas Potter, in " Concrete, its uses in Building " 
(Bats(ord). says : " Concrete retaining walls — i.e.. walls which uphold or retain the 
natural or artificial ground on one side, are not so liable to develop cracks as 
ordinary walls, because they are exposed to climatic influence on one side only, and 
so maintain a more uniform temperature. All the same, they do occur, and for 
this reason some engineers insert a thin piece of wood or sheet iron verticallv, 
from top to bottom of walls, and at fixed distances apart. These are only 
carried a few inches into the wall, and fair or flush with the surface ; when 
the concrete is dry they are withdrawn, and the space filled up with mortar or 
cement. This space probably opens and closes more or less when exposed 
to extremes of temperature, but is scarcely an eyesore in the sense that an 
irregular-shaped crack would be ; it is thought that the shrinkage does not affect 
the wall beyond the space divided by the wood or iron strip, but that the former 

B 383 



RETAINING WALLS. [CQNCBETFJ 

retains a sound condition. Sometimes, where it is not practicable to store cement 
a sufficient time to season it, low walls wiU show horizontal fissures or cracks 
between each ' lift ' or layer of concrete, or where the latter has been left for a 
time before another deposit has been made. These are caused by the unsea- 
soned cement swelling and bringing about the same result as the use of hot lime ; 
we often see the lime constituent of the cement oozing through these cracks or 
fissures in the form of milk of lime. Concrete retaining embankment walls of 
railways have many of these unsightly horizontal fissures." 

Before describing the modern reinforced concrete walls, reference may be 
made to a very large one of mass concrete recently constructed at Los Angeles. 
It is 600 ft. long, 52 ft. 8 in. maximum height down to a minimum of 13 ft., and 
is surmounted by a 5 ft. parapet. The foundation at maximum height of wall 
is 14 ft. wide, and the wall 8 ft. to 3 ft. at base of parapet. It was constructed 
in 40-ft. sections, no two adjoining sections being built at the same time. The 
expansion and contraction joints alternate, a distance of 80 ft. existing between 
two expansion joints or two contraction joints. The expansion joints were made 
by nailing sheeting across the end of the section, and properly bracing it ; the 
expansion joints were reinforced with pilasters. The contraction joints were 
formed midway between the pilasters by bringing the end of one section of the 
wall up to a true vertical plane at a right angle with the central line of the wall. 

An early form of reinforced concrete retaining wall is shown in Fig. 6 (Plate 
I.), which is a typical cross-section of some waUs built by the Chicago, Burlington 
and Ouincy Railway. The very moderate amount of reinforcement necessitated 
the retaining of a fairly large mass of concrete. Fig. 7 (Plate II.) shows a 
somewhat similar wall combined with a fence, built by the Michigan Central 
Railroad Co., but in this case the reinforcement was more to ensure the 
stability of the fence than the wall, as the wall would probably have been 
quite efticient without it. To provide for any unequal character of the 
foundation, six i-in. square rods were placed longitudinally at the bottom of 
its broad footing. According to the Engineering Record, the fence surmounting 
the wall is a 6-in. continuous vertical slab 7 ft. high, that is built with both 
faces smooth. This slab is reinforced i"25 in. from both faces with a plane 
of i-in. square rods, spaced vertically i ft. apart on centres and extending from 
its top down into the wall. The rods near the rear face are carried entirely 
to the bottom of the wall, while those in front terminate directly above the 
footing. The fence slab thus is anchored thoroughly to the wall, it also 
is reinforced longitudinally by three pairs of horizontal i-in. rods, one pair^ 
near the bottom, a second midway of its height, and the third just below the top, 
as shown in the drawing. These longitudinal rods are added chiefly to provide 
for temperature stresses, although they are of considerable value in strengthening 
the slab. Expansion joints are placed 25 ft. apart in the wall to confine to definite 
points the opening that may be I'aused by temperature changes or settlement. 
The longitudinal rods in the slab, and three horizontal rods near both faces of 
the wall, are broken at these joints. The concrete in the wall and fence was 
made quite wet, in the proportions of one part cement, 2"5"parts sand, and 4-5 

38+ 



r j.CON.MDIirrjMMAU 



RBTA/MNC WALLS. 




Plate I. Details orrRET 



33j 



RETAINING WALLS. ICQNCBETE] 

parts broken stone ranging in size from J-in. pieces to those which would pass a 
screen with i'5-in. meshes. 

Fig. 8 (Plate II.) shows the type of wall designed by Mr. C. E. Rork.of the 
Steptoe Valley Smelting & Mining Co. He also constructed a designing diagram 
from which the section for any given height could be readily obtained. Details of 
this diagram were given in the Engmeering Record for 19th February, igio. 
The advantages claimed were : (i) Economy of work and time in the draftirg 
office ; (2) economy of excavation ; (3) the toe being outside avoids either under- 
cutting, where the ground is of such a nature as to admit of that, or filling in if 
the ground has to be cut awa^' to get at an inside return toe or heel ; (4) the 
outside toe serves as part of the floor, where that is to be of concrete, and thus 
saves material ; (5) the form work is of the simplest and allows of repeated 
re-use of forms. 

Fig. 9 (Plate II.) shows a simple reinforced concrete wall of L section, 
where the weight of the earth causing the thrust helps to hold the wall 
in position against the thrust. It was at one time thought that this 
form was not economical for greater heights than 12 ft., but Mr. F. A. Bone, 
of Cincinnati, has shown that they are suitable up to as much as 36 ft. 
high. Where the foundation was liable to compression, or where it was 
desired to avoid excavation at the rear of the wall, the section of an 
inverted T as shown in Fig. 10 (Plate II.) was found preferable. In this design 
the wall has absolutely no tendency to ov-erturn with any load not greater than 
that assumed, and has no tendency to unequal settlement as the pressure is equally 
distributed over the foundation. The resistance of this wall to sliding forward 
on the base is less than in Fig. 9, as the weight is less. The tendency to slide is 
not excessive, as the angle of friction is but 23°. However, to make the resistance 
equal to that of the gravity wall, a key is extended into the foundation. The 
construction of this type of wall is much simpler than for a counterfort wall. 
The forms cost less than for a concrete wall of the same section as the gravity 
wall shown at Fig. 3. The reinforcing is all simple, with no bent rods. 

A very good form of section for an independent retaining wall was that 
adopted in the Royal Liver Building, Liverpool, shown in Fig. 11 (Plate II.). The 
foundation slab is bardered by retaining walls of this section extending all round 
the site, thus converting the basement of the building into a huge watertight com- 
partment, virtually identical so far as regards construction with a waterworks 
reservoir of more than 6,000,000 gallons capacity. One incidental result is that 
the lowest storey will always be perfectly dry, and therefore quite suitable for 
offices and the storage of papers. This is a point of considerable practical import- 
ance in view of the fact that the subsoil water level sometimes rises to the height 
of 10 ft. above the basement floor line. The wall consists of a 5 in. vertical slab 
with a continuous coping 18 in. wide by 8 in. deep, an extended base as shown 
by the drawing, vertical counterforts at short intervals apart, and horizontal 
ribs projecting from the slab and connected with the counterforts. 

Fig. 12 (Plate II.) shows the section adopted by the Delaware. Lackawanna 
& Western Railroad at Buffalo. It consists of an L section with reinforced, 
counterforts, which are called buttresses by the American engineers. 

3S6 



r y , ItDNSTRUCTIONA 1.1 



R/iTAIMXC WALLS. 



M/5-[- 


'^.T: 


^""' -■""'- 


:[ 


\ 


f* ' shrink a^ . .' 
/8'cenCnes 






^ Vb' rods 
5* centres 


- , 




:"- 






Retaining Walls. 



387 



RETAINING WALLS. 



[C^CBETE] 



The tracks were placed near retaining'walls only where the buttressed section 
was used, the distance from the centre of the track to the back of the wall in no 
case being less than 7 ft. 6 in. No tracks whatever were close to the section 
without buttresses, the retained fill having a long slope up to the road-bed level. 
The earth pressure against the walls, which are 2 ft. thick, was figured according 
to the formulas in Church's Mechanics, the height of earth being taken at 100 lb. 
per cubic ft. The weight of concrete was taken at 150 lb. The pressure due to 
the moving loads on the tracks was figured for Cooper's E 50 loading. The width 
of the base for the buttressed type was taken as half the height of the wall above 
the top of the base plus 2 ft., and for the L section as half the distance from the 
top of the base to a point where a vertical line through the inner edge of the base 
intersects the slope line, the slope being li : i. The base is 2 ft. 6 in. thick. 
The stresses in the steel were kept under 16,000 lb. per square inch, and in the 
concrete under 500 lb. 

The reinforcement of the buttressed section consists of both horizontal and 
vertical bars near the face of the wall, horizontal bars in the base and inclined 
bars in the buttresses, square mild steel being used in all cases. Those laid 
horizontally in the face of the wall are of |-in. material spaced on different centres, 
farther apart at the top and closer at the bottom, to take care of the increasing 
pressures toward the bottom of the wall. The vertical bars in the front face are 
of |-in. material spaced throughout on 2-ft. centres. In the back face five -J-in. 
bars have been placed on 18-in. centres. There are tie rods from the wall into each 
buttress, two of them being looped over every third of the horizontal face bars. 
They are 6 ft. long and J in. square. The heaviest bars used on the work, i^ in. 
square, are used for the diagonals in the buttresses. There are eight of these, but 
only four run the entire distance from the top of the wall to the outer end of the 
base, the others starting at intermediate points. At the bottom of the buttresses, 
four of the diagonal bars are bent back toward the wall and are embedded near 
the under side of the base. Running longitudinally in the top of the latter are 
i-in. square bars, in the outer half of the footings. The rods in the face do not 
come closer than 2i in. to the surface of the concrete, and those in the buttresses 
and in the base not closer than 35 in. 

In order to preserve the proper spacing for the horizontal bars in the face, 
a 2-in. by 2-in. by ili-in. angle is placed in the face at each buttress, holes being 
punched in one leg to hold the bars in their proper positions. They are left in 
place and form part of the permanent reinforcement of the wall. The horizontal 
bars are on 18-in. centres for the first 6 ft. down from the top, on 12-in. centres 
for the next 6 ft., on 9-in. centres for the next 5 ft. 3 in., and on 6-in. centres for 
the remainder of the distance to the bottom of the wall. 

The reinforcement for the sections below 24 ft. and above 12 ft. m height 
is substantially the same for all sections, except that the base would be moved 
upward, cutting off the lower part of the reinforcement shown in the diagram, 
so that from the top down, for any given distance, the steel will be the same in 
walls of all heights. 

The buttresses are 2 ft. wide and 12 ft. 6 m. on centres. In the original 
design it was intended to place an expansion jomt every 25 ft., or on the centre 

388 



T/. cc/N.vnJiirnoNAi.i 



R !■: TA I X I N G \ V A L L S . 




RETAIMNG WALLS. [CQNCREJE] 

line'of "every second|buttress. When construction was started, however, it 
was found that the wall could be more economically placed in 50-ft. than in 25-ft. 
sections, and it was therefore decided to place the expansion joints every 50 ft., 
so that the day's work could be made to terminate at an expansion joint. 

All of the horizontal bars are 28 ft. long, while the others, necessarily, are 
cut to shorter lengths in accordance with their positions. The concrete was a 
1:3:6 mixture made with gravel. 

Fig. 13 (Plate III.) shows the section of a reinforced concrete retaining 
wall about 220 ft. long with a maximum height in the centre of 64 ft. 
exclusive of a 4-ft. parapet wall constructed by the Department of Public 
Works at Pittsburg. The wall spans a guUey which was formerly crossed 
by a timber trestle bridge. Briefly stated, the wall consists of a reinforced 
concrete face and footings or floor, with reinforced counterforts at frequent 
intervals. The character of the ground introduced some complications 
into the design of the footings, and between successive counterforts 
hardly any two slopes of the footings are alike, the maximum being about 38° 
parallel with the length of the wall, and about 30° transversely. The 
footings were sloped transversely instead of being made horizontal, not only 
to save e.xcavation, but also to save concrete. The ground consists of a layer 
of loose material, beneath which is a bed of excellent shale, on which the footings 
are founded. The floor between the counterforts is 2 ft. thick, the front wall 
18 in. thick through its full height, and the counterforts i ft. thick. The concrete 
in the floor and the foundations consists of i : 2i : 5 mixture ; and in the face 
wall, parapet and counterforts a 1:2:4 mixture, the sand being washed river 
sand, and the aggregate gravel. The reinforced concrete portion of the wall 
has not been carried across the entire length of the hollow, there being a plain 
concrete gravity section 18 ft. long on the east end, and 22 ft. long on the west 
end. Two vertical expansion joints have been provided at approximately the 
third points in the length of the wall, 74 ft. apart. These expansion joints are 
V-shaped, and filled with three thicknesses of heavily- tarred paper. 

The reinforcement consists of round rods varying in diameter from J to 
if in., and anchored to plates embedded in the floor and in the face of the wall 
by nuts and pins. These anchor plates are all | in. thick, and are 8, 8 J or iii in. 
wide, depending upon the height of the wall where they are used. One of these 
plates runs the entire length of the floor embedded in the latter under each counter- 
fort, and another plate is embedded vertically in the wall in the same plane with 
the floor plate and the centre line of the counterfort. These two plates are tied 
together by round rods varying in diameter from i:|: in. at the lowest section of 
the wall to if in. at the highest, their spacing and number being naturally depen- 
dent on the earth filling which they are to retain, the weight of the latter varying, 
of course, with the height of the section. .At each end of these rods there is a 
forked eye, and the connection is made to the plates by means of pins, which, 
after being driven, are held in position by two split cotter pins. In the lowest 
sectionof the wall twelve i-in. round rods are used, their spacing in the anchor 
plate embedded in the floor being 9J in. on centres. From the floor anchor plates 
the rods spread out, the pins which connect them to the vertical anchor plates in 

390 



fy. ICiN.TUDCIlONAll 
K^ £NlilNli.H>lN(i ~J 



RHTA IN INC WA LLS. 



Sccrie o/" fecc 






AT 



IVf 



i 



B 



& 




-'lir 



FIC.20 




FiC 21 




Plate IV. Dltails of Retaixikg W^. 



39' 



RETAINING WALLS. 



1CQNCBETE3 



the wall being 13 in. apart at the bottom and 41 i in. apart at the top, varying 
gradually between these two values. In the highest section of the wall there 
are forty- two ij-in. round rods embedded in the counterfort, their connections 
to the floor anchor plate being 8J in. apart, and in the wall anchor plate 10 in. 
at the bottom and 6 ft. 3 in. at the top, varying, as described for the lower section, 
between these two values. The pins used in connecting the rods to the plates 
vary from iJ to 2^ in. in diameter. 

The floor rods in any given sections between two adjacent counterforts 
are all of the same diameter, varying from nineteen i^-in. rods where the wall 
is lowest, to fifty-three ij-in. rods where it is highest. Rods of smaller size have 
been used in some of the other panels, and the required total section made up by 
using a larger number of rods. The anchor plates have three lines of holes punched 
in them, the upper hne in the floor anchor plate being for the connection with 
the tie rods running through the counterfort, and the other two lines for the 
reinforcing rods in the floors. All of the floor rods on one side of the counterfort 
are connected through one line of holes, the rods on the other side being connected 
through the other hne of holes. Nuts are used on the ends of all of the reinforcing 
rods in the floor and in the wall. The length of the footings varies from 9 ft. 
to 29 ft. 6 in. in length, and the spacing of the reinforcing rods in them is always 
uniform in any given panel. All of the rods are bent downward, and though 
the tops of the floor anchor plates are about on a level with the floor itself, the 
rods come within a few inches of the bottom of the concrete footings. 

The reinforcing rods in the face of the wall are of the same general type as 
those used in the floor, and are passed through the vertical anchor plates, in the 
planes of the counterforts, and held in place by means of nuts. Each rod spans 
between two adjacent counterforts. They varv in diameter from l in. at the 
bottom to i- in. at the top, the spacing increasing from the bottom upward to 
suit the varying pressure of the earth backing. This spacing varies from 3 in. 
at the bottom of the highest section of the wall to 6 in. at the top of the same 
section. The number of the reinforcing rods in the face varies from 53 in the end 
panels to 151 at the centre. 

The counterforts are spaced 10 ft. apart on centres, except at the two expansion 
joints, where they are on 4-ft. centres. They are all i ft. wide and enclose the 
tie rods which connect the anchor plates in the floor and the face. 

Fig. 14 (Plate III.) shows a section of a retaining wall for a 50-ft. roadway 
by the Indented Steel Bar Co.. Ltd., and Fig. 15 (Plate III.) a somewhat 
similar wall with counterforts and apron given by Mr. P. H. Palmer in The 
Surveyor, 14th July, 1905. 

The retaining wall of the Royal Insurance Co.'s building at the corner of 
St. James's Street, Piccadilly, is shown in Fig. 16 (Plate III.). The wall 
is 24 ft. 6 in. deep from top to sub - basement level, and only 30 in. thick 
at bottom, tapering to 9 in. at the top. The reinforcement for the vertical 
part of the wall consisted of i|-in. indented steel bars spaced 45 in. apart 
for a height of 14 ft., and the remainder of the height 13J in. apart, every 
third bar being carried to the full height. A double system of similar 
remforcement, spaced 4i in. apart, was introduced into the horizontal portion 

392 



RETAINING WALLS. 



of the wall, and binding bars, which are not shown, were inserted in the front 
edge to assist the concrete in taking the compressive stresses. The concrete was 
all machine mixed, and consisted of r cement, 2 sand, 5 Thames ballast graded 
from .J in. to J in. 

.\ retaining wall on the Kahn system of reinforcement is shown in Fig. 17 
(Plate III.) ; this may be compared with the mass concrete wall having a 
similar surcharge shown in Fig. 3 (Plate I.). The intermediate shelf on 
the back of the wall, dividing into two portions the wedge of earth which 
]iroduces the thrust, reduces the thrust by about one-half. In the Morning 
Post building, in .Mdwych, London, although steel frame construction was 
utilised for the general building and foundations, the retaining wall which 
surrounded the site was only of mass concrete. It had, however, some novel 
features, as shown by Fig. 18 (Plate III.). The toe of the wall gives 
increased resistance to sliding, and the stanchions being placed upon the foot 
of the walls give additional stability. A brick wall was first built against the 
soil and then watcri)roofed by mastic asphalt, the concrete being afterwards 
deposited within shuttering. The danger of letting in the street, by reason of 
the pro.ximity of the tunnel through which the London County Council trams run, 
and the Gaiety Theatre and Hotel, necessitated great care in the work, and only 
small portions at the time could be constructed ; an efficient bond between the 
different lengths was, however, obtained by leaving a V-shaped groove at each 
junction. 

In the General Post Office extension, carried out under Sir Henry Tanner 
upon the Hennebique system, the retaining walls, shown in outline in Fig. 19 
( Plate IV.), were strutted by the lower floor, and therefore became equivalent to 
the flat plates in the sides of a tank. The panels were only 7 in. thick at the 
top, and 8 in. thick at the bottom, with a total height of 26 ft. 6 in., whereas 
a solid brick retaining wall would have needed to be about 8 or 10 ft. thick at the 
base ; the comparison of the two sections given in the Builder, 3rd April, igio, 
and shown in Fig. 20 (Plate IV'.), indicate the striking advantage of using 
reinforced concrete in this manner. 

.\ further departure from normal methods of constructing retaining walls 
was carried out at the Royal Insurance Offices in Piccadilly, London, by which 
much valuable space is sa\ed. This consisted in forming the vaults under the 
pavement in conjunction with the wall, as shown in Fig. 21 (Plate IV.). A 
very similar arrangement appears in JMessrs. Mappin & Webb's premises at the 
corner of Cheapside, London, just completed, where the double cantilever arrange- 
ment is still more pronounced, as shown in Fig. 22 (Plate IV.). 

This summary of the development of retaining walls has shown the ver\' 
great advantages obtained by the adoption of reinforced concrete, and these 
advantages, consisting of a saving of cost, space and time, without any sacrifice 
of durability, assure a successful future for this method of construction. 



393 



THE CONCRETE INSTITUTE. 



[CDNCRETEJ 




THE CONCRETE 

INSTITUTE: 
VISIT TO PARIS. 

By F. E. Wenlworlh.Sheilds, M.Inst.C.E. 

H„ii Sec. of the det'iilalin,, 



We are very pleased lo te jtle to n,Te some particulars of the recent -visit paid ty a 
deputation from the Concrete Institute to Pans, ivhich tvas undertaken to inspect some of the 
earlier examples of reinforced concrete, lo ascertain the durability of this material. We hope 
at a later date to be able to publish the report of the Institute on the various structures 
inspected.— ED, 



A SERIES of meetings, the importance of which can hardlv be overestimated, 
was held in Paris during the month of April, when a deputation from the 
Concrete Institute was invited to visit that city and to examine several most 
interesting works in reinforced concrete which have been constructed there 
during the latter half of the last century. The deputation consisted of Sir 
Henry Tanner, LS.O., F.R.I.B.A. (Vice-President of the Institute), Mr. C. H. 
Colson, M.Inst.C.E. (Admiralty Works Department), Mr. Wilham Dunn, 
F.R.I.B.A., Mr. W. G. Kirkaldy. Mr. A. Ross, M.Inst.C.E. (Chief Engineer Great 
Northern Railway), Mr. J. S. E. de Vesian, M.Inst.C.E., Mr. F. E. Wentworth- 
Sheilds. M.Inst.C.E. (Docks Engineer, Southampton), Mr. E. P. Wells, J. P. 
(Hon. Treasurer of the Institute), Mr. H. K. Dyson (Secretary), ^Mr. H. K. G. 
Bamber, Captain Gibson-Fleming, R.E., Mr. Fred A. White (Chairman of the 
Associated Portland Cement Manufacturers (1900) Ltd.), Mr. G. C. Workman, 
Mr. P. W. Leslie, Mr. Harold H. D. Anderson, and Mr. P. M. Eraser. 

The programme of visits was arranged by Monsieur Rabut, Engineer-in- 
Chief of the French State Railways, who has himself designed and carried out 
some notable works in the new building material, and who has done much to 
popularise its use among the famous Government Corps of Engineers (I.es 
Ingenieurs des Fonts et Chanssees), of which he is a distinguished member. 
Besides having control of all the new works on the State Railways. M. Rabut 
is a professor in the school where the students of the corps receive their training ; 
and it may be here pointed out that the next generation of French Govern- 
ment Engineers will derive immense advantage from having studied under one 
who has so thoroughly mastered not only the theory but also the practice of 
reinforced concrete design. 

M. Rabut had been specially asked by the deputation to show them works 
in reinforced concrete which had been in existence for a number of years, and 
which had been exposed to changes of climate, moisture, and other trying condi- 
tions. Accordingly he put himself into communication with other French 
engineers who have specialised in this material, and prepared a programme 
of visits which occupied two long days, during which a number of structures 
unique in their variety and ingenuity of design were inspected. 

39+ 



VISIT TO PARIS. 



The lust morning a start was made by visiting the church of St. Jean de 
.NFontmartre, in Paris. This was shown by the architect, M. de Baudot, who 
occuiiios (lie position of Inspector-General of Historic Monuments to the French 
Go\crunicnt. I'nfortunately Monsieur Cottan(,-in, who had carried out the 
work on tiic svstcin which hears liis name, was unable to be present. .As will be 




seen from the longitudinal section on page 396, the church is built on steeply 
sloping ground, and the eastern end contains a basement, which is itself a fine 
chapel. The church, which is built partly of brickwork and partly of concrete, 
both reinforced, is about sSmetres (125 ft.) long and 28 metres (92 ft.) wide, 

305 



THE CONCRETE INSTITUTE. 



[g3NCRETEJ 



and with a total height of about 30J metres (100 ft.). The principal building is 
approached from the main street, where a fine view of the west front is obtained. 
The curious flat effect of the facade, with its parapet looking as if it were made 
ofjlace, and the light belfry tower surmounting it, at once betraj' the fact that 
unusual building materials have been employed. The walls are of very thin 
red brickwork, the bricks being hollow, and reinforced horizontally and vertically 
with steel wires on the Cottancin system. The columns and arches are red 
brick casings surrounding a reinforced concrete core. The roof vaulting and 
the floor are of reinforced concrete. The interlaced arches of the balustrade 
and of the belfry tower are made with the same material and pleasantly deco- 
rated. The whole is a marvellous piece of light and strong design. il. de 
Baudot has paid much attention to the problem of decorating concrete, and 




Longitudinal section, showing chapel in has 
CHtRCH OF Sr. Jeas de Montmartre. I 



has here produced very pleasing effects by a kind of bold mosaic of coloured 
pottery discs fastened on to the concrete surface. He claims that the church, 
which was built in 1896, has cost far less than any building of its size could 
have done if carried out in other materials, and certainly /i6,ooo for such a 
large building seems to be a moderate sum. 

The deputation next passed on to the Canal St. Martin, a portion of which 
(le Basin du Temple) was roofed over three years ago with a reinforced concrete 
arch, which is remarkable in many ways. The canal at this point is in a cutting, 
the total depth from the ground surface being about 9 metres (30 ft.). The 
sides of the basin were originally formed of masonry retaining walls, arranged 
as shown in the accompanying cross-section, which gives the principal dimen- 
sions of the structure. The new roofing has a span of 27-60 metres (90 ft.) and 



■ ENOINEEJ^INd — J 



l7S/r TO PARIS. 



a total k'litjth <if 240 metres (790 ft.). To provide for any slight subsidence 
of the abutments, which were suj)portcd on the old retaining walls, the arch, 
which is 45 cm. (18 in.) thick, is provided with three continuous joints ("semi- 
articulations ") of peculiar design. These joints were formed by a series of 
special bars nearly (but not quite) circumferential, which crossed each other 
in such a manner that all passed through the centre of the joint. The detail 
drawing explains this clearly. The ordinary circumferential reinforcement, con- 
sisting of round bars above and below, 16 mm. (i in.) diameter and 20 cm. 
(7J in.) apart, stopped short on either side of these joints. .\s a precaution the 
arch is stiffened with reinforced concrete ribs at inter\'als of 13 metres (43 ft.). 

Cross section of roofing. 

f>Mc 




r^->s^^^^^^<!^'.'4,.^-^- .^S?^"riSiV^^?!^^''-'*''"~'^''<?i^^f?^ I 



/I'ffftd^ de fO 




/ fXfUfr.^' a:e //7''^ 


15^^ 


>v= ==■-<;. ■---■-■jr -.-;--»»:-;- 


------H 


\ :---^-^^ 




<;^.,..;-.!..,j>.-s;;^5;;^ 


^s^ 



Jp/4r. i/^ rrroutr. 




Detail of joint. 
Canai, St. ^rAR.l^. Paris. 

although it is estimated to be sufftciently strong without these ribs. The 
cost of the arch and its foundations was about /26,ooo. Above the roofing the 
ground is filled in to a level surface, while the~towing paths below are carried 
on cantilever slabs of reinforced concrete. 

In the afternoon a visit was paid to a most interesting house at St. Denis 
built no less than 58 years ago by the elder Coignet, who is claimed to be the 
mventor of reinforced concrete in the modern sense of the word. Certamly 
he seems to have been one of the first who clearly understood the part played 
by the reinforcement in his structures. The house in question is a three-storey 
buildmg about 20 metres (65 ft.) by 14 metres (46 ft.). The roof consists of 
a slab of reinforced concrete about 30 cm. (i ft.) in thickness resting on brick 
walls. By means of partition walls the unsupported span of any portion of 

39: 



THE CONCRETE INSTITUTE. 



[CQNCRETEJ 



the roof IS reduced to about 6 metres (20 ft.). The concrete, curiously enough, 
is a mixture of very fine gravel and hydrauhc hme and cement mixed in the 
nroDortions of 5 : i : '■■ The reinforcement consists of H-bars about 8 cm. 
i, in ) deep placed neaV the underside of the slab so as to take the tension. The 
concrete was broken into in the presence of the deputation, and it was found 
that both the steel and concrete were m excellent condition. A large number 
of small contraction cracks were to be seen m the surface, which had apparently 
been stopped up with cement. There was no rendering or any sort of covering 
on the roof however, and inquiries made from those who were hvmg in the 
house elicited the fact that the roof is perfectly watertight m all weathers. The 




built by 1 I 
Roof of 



house was shown by the son of the famous builder, M. Edmond Coignet who 
t himself well kno.'. as having designed and erected many important structures 

" 'i:^^ rXnoon the deputation were mvited to see the famous ™^ 
disposd works of Paris, and these proved to be full of interest to the student o 
re nforced concrete. The Engineer-in-Charge. M. Bechmann, Ingenieur en Chef 
des Fonts t Chaussees, and M. Coignet and M. Bonna, who are responsible for 
S deta Is and for the execution of many of the works, arranged the programme. 
Briefly he sewers of Pans are led to Clichy, where the first mam pumping 
Sn is placed Here the pumps force the sewage through a syphon under 
£ Sv r Seine mto a gravitation culvert leading to Colombes, where anothei 
pumpmg station is situated. At this pomt the pumps send the sewage across the 

398 



VIS/r TO I'ARIS. 



river again, this time on a bridge, and then through a pair of rising mains, whose 
length is abnit 2A kilometres (li miles), with a total lift of about 34 metres 
(ill ft.). Thence it passes into a single gravitation culvert of 3 metres (10 ft.) 
diameter, and with a length of about (^ kilometres (4 miles). After that the 
ground falls rapidly down to the irrigation farm at Acheres, and the sewer falls 
with the ground At this descent the sewage is carried in two pines, each of 
100 metres (3 U. 3 111.) iliameter. At the base of the slope the pipes pass once 
more under the ri\er, and thence into branch pipes, which connect with the dis- 
tributing feeders of the irrigation ground of Acheres. 

Reinforced concrete has been very largely used througliout the whole of 
this main sewerage system. For instance, the long rising mains which lead 
liom the second pumping station at Colombes consist of two pipes, each 




~''^^™"="*='''''^^j>^^^ 



Cross section of ttiniiel comainin;; two, rising main 

PaKIS StWKKAOE 



rSo metres (6 ft.) diameter, iniilt inside a cut and cover tunnel, which serves 
to give access to the pipes. This tunnel is entirely of reinforced concrete. Its 
length is about 2* kilometres (li miles). It is almost semi-elliptical in form, 
and its cross-section is shown on the accompanying figure. It has a width of 
516 metres (17 ft.) and a height of 3-34 metres (11 ft'.). The floor is made of 
a slab of plain concrete of varying thickness, but the arch of reinforced con- 
crete has a uniform thickness of q cm. (3J in.). The reinforcement consists 
of round bars placed longitudinally and circumferentially. The skin is hardly 
concrete 111 the English sense of the word, but a mortar of cement and sand 
mixed in the proportions of about i to 3. This, moreover, is rendered inside 
with a mortar of Vassy cement and sand mixed in the proportions of about 
I to li. The result appears to be excellent, as the tunnel is absolutely dry, 
and after its 17 years' work shows no sign of distress. Within this tunnel are 
placed the two rising mains, each of rSo (6 ft.) diameter. The lower portions 

399 



THE CONCRETE INSTITUTE. 



[CDNCBETEJ 



of these mains, where the pressure is greatest, are made of plate steel. The 

upper portions are reinforced concrete pipes made on the Bonna system. These 

are designed to stand a maximum working head of 17 metres (56 ft.) at the 

lower end. They consist of a very thin steel tube, 4'5 to 3'5 mm. (o'i8 to 014 in.) 

in thickness, which forms the internal lining of the pipe. Outside this steel 

tube is a skin of concrete or mortar 10 cm. (4 in.) in thickness, containing the 

reinforcement, which consists of bars of the cross-section used by M. Bonna, and 

which are placed both longitudinally and circumferentially. The pipes are cast 

in lengths of 2 50 metres (8 ft.), and each joint is covered by a collar of similar 

V2 Coupes 

Suivanl I'axe ,...<:^^^^^^^^^^;::^>^enij>e deux conlreforls 
dun contrefort 




design to the pipes themselves. Each length of pipe is supported by a concrete 
saddle, which rests on the floor of the tunnel, .^t the top of the hill the two 
rising mains discharge into a single gravitation sewer, a portion of which is 
constructed of reinforced concrete. It consists of a barrel culvert 3 metres 
(10 ft.) in diameter and 9 cm. (3I in.) thick, reinforced with round bars placed 
longitudinally and circumferentially. Here, again, the concrete consists of a 
mixture of cement and sand, and the culvert is rendered internally with a 
strong mortar i cm. (j in.l thick. It is supported on saddles of reinforced con- 
crete at intervals of 4'20 metres (14 ft.), which rest on a continuous slab of 
plain concrete 4J metres wide and of varying thickness. This part of the 
culvert stands above the surface of the ground. From the end of this gravita- 






VISIT rO PARIS. 



tinn cuh-fil the sewage onro mure enters a pair of east-iron ])ipes. through 
wliieh it is taken into the Seine Valley, crossing under the river once more to 
the irrigation ground at Acheres. Here, again, the branch distributing pipes 
are of reinforced concrete on the Bonna system. The design of these latter 
])ipes is slightly different, however. The thin steel tube is still preserved with 
the stiff reinforced concrete casing outside it. A casing of concrete is, however, 
))rovided inside the tube as well as out to ensure the preservation of the sheet 
steel. This inside lining is itself reinforced similarly to the e.xtcrior covering, 
but the section of the bars is much lighter. The thickness of the concrete is 
also less inside than mitsido. Piites of all size< from fio metres (3 ft. 6 in.) 




to 030 metres (i ft.) are made in this fashion to conduct the sewage to various 
parts of the irrigation ground. They are all cast in short lenirths and laid ;n 
position, each joint being covered by a reinforced concrete collar. 

Besides being used in the culverts and pipes here described reinforced con- 
crete has been largely used at the pumping station at Clichy. .A. large quantity 
of the sewage is pumped into a circular tank (la Bache de Gennevilliers). which 
is 6'20 metres (20 ft.) in diameter and 050 metres (31 ft.) high. This is formed 
of reinforced concrete 9 cm. (3^ in.) thick, surrounded on the outside with an 
ashlar masonry wall for the sake of appearance, as the tank stands \vholl\- 
above ground. The rest of the sewage is discharged into a large rectangular 

2 401 



THE CONCRETE INSTITUTE. 



[cqncbetE 



..nk with a cu-cular end tn it (la Bache d'Acheres). The rectangular portion 
is about 20 metres (hh ft.) by 8 metres [zh ft.), and the circular end is 6 metres 




f.o ft ) m diameter. This latter tank, which lies undergi-ound, is constructed 
of masonry, but is covered throughout with a fiat mof of reinforced concrete. 
402 



I /. C&N.VI pin-noNAi-i 

V'i- LN(.INt.li.KlNr. ~i 



VISIT TO PARIS. 



On the second morning the party was invited by M. Hennebiquc, whose 
name is so well known in Ibis connirv in connection with reinforced concrete, 



/ 




to see his honse in Paris, No. i Rue Danton. The building contams a very fine 
set of offices for the use of ^I. Hennebique and his staff'. Later on they visited 

403 



THE CONCRETE INSTITUTE. 



ICDNCBETE) 



M. Hennebique's country house at Bourg-Ia-Reine, which is certainly a marvellous 
instance of what can be done with reinforced concrete. A glance at the accom- 
panying illustrations will show some curious architectural features. The overhanging 
room at the left-hand side of the picture on page 402, and the high tower with its 
water tank, are, of course, effects which it would be almost impossible to obtain 
in any other material. It may be interesting to mentiun that the surface of this 
building is formed of very thin reinforced concrete slabs, in which coloured 
flints are embedded. The monotonous colour of concrete is thus pleasantly 
avoided at little or no expense, as the use of the slabs renders planking for moulds 
unnecessary. 

In the aftcrnnnii the widening wnrks of the Paris-Autcuil Railwav were 




visited, under the guidance of M. Rabut, the Engineer-in-Chief. This is a line 
with exceedingly heavy traffic. Some ten years ago the number of lines of 
way was increased from two to four over a considerable length, and now works 
are in hand for a further widening. The line is largely built in two cut and 
cover tunnels, with upright masonry walls and flat roof, the span between the 
two walls being about 13 metres. In the older tunnels this roof was constructed 
of steelwork, but in the newer ones reinforced concrete has been freely used. 
The roofing consists of stout reinforced concrete T-beams, 80 cm. (2 ft. q in.) 
in depth and 2'50 metres (8 ft.) apart, the slabs being 30 cm. (i ft.) in thickness. 
M. Rabut is quite satisfied with the suitability of reinforced concrete for such 
a position, although the conditions are extremely trying, as sulphurous smoke 

404 



L^ 



\7.S/r TO PARIS. 



[uh\ steam liinii tlic eiij^'ines are constantly being discharged on to the roof. On 
the other hand, Ik- liiitls that the steel girder roofing f)f the older tunnels corrodes 
si'ry rapidly, and he is gradually covering all these steel girders with a cloak 
of reinforced concrete. One of the most interesting works on the railway, 
however, is the cantilevers which are being canstructed to carry an overhead 
roadway alongside the railway. The line at this point is in cutting, and was 
originally bounded by a masonry retaining wall, which su])ported the high- 
level roadway alongside. It became necessary to widen the line without dis- 
turbing the roadway. Accordingly a new masonry retaining wall under the 
( tntre of the roadway was built, from which projects a series of reinforced con- 
irete cantilevers connected with concrete decking. These are tied back to a 
masonry counterbalance, which is built under the centre of the roadway. The 
ilrawint; and ph(it<igra|>h clearly illustrate this construction, which is a s])lendid 





example of M. Rabut's engineering skill, and there is much credit due to 
JM. Hennebique, who has carried out the work for him. The cantilevers vary 
in length, the longest being as much as 7 metres (23 ft.). 

A very ingenious use of composite beams is being made by M. Rabut in 
the lengthening of certain over-bridges. One of the roads which cross over 
the railway is carried on six longitudinal plate girders of 40 metres (131 ft.) 
span, with substantial jack arches of brickwork in between them. Owing to 
the addition of two more lines of way this span has had to be increased to 
48 metres (157 ft.). At first it was proposed to remove the girders and sub- 
stitute other stronger ones in the usual way, but M. Rabut pointed out that 
it would be quite possible to make use of the e.xisting girders, and merely 
lengthen them. This he said because in calculating the strength of the original 
girders no account was taken of the jack arches between the girders, which 
support the roadway, and in which the top flanges of the mam girders are buried. 
In the light of our present knowledge, however, he considered it safe to assume 



405 



THE CONCRETE INSTITUTE. [CDNCBETE] 

that this mass of brickwork added very considerably to the strength uf the 
steelwork, and that the span might safely be increased without renewing this 
steelwork. Accordingly the girders have been prolonged to the same design. 
Careful tests with traction engines and loaded wagons have been made, which 
show that the deflection is very considerably less than would have been the 
case if the brick arches did not exist, and that the bridge as widened is perfectly 
safe to take any load that may come upon it. It is evident that by thus utilising 
the existing girders an enormous economy has been effected. 

While in Paris the deputation had the honour of bemg invited to meet 
the Association des Ingenieurs des Fonts et Chaussees at dinner. In the 
absence of M. L'Inspecteur-General Guerard, the visitors were received by 
M. Colson, some time Inspecteur-General des Fonts et Chaussees, and well known 
to Englishmen as a leading authority on inland navigation. The deputation 
were also very kindly entertained to luncheon by the Chambre Syndicale des 
Constructeurs en Ciment Arme, a society which includes nearly all the leading 
constructors in reinforced concrete in France. M. Edmond Coignet, the Pre- 
sident, received the guests. They were also entertained by M. Hennebique at 
his house at Bourg-la-Reine. Before they left France an opportunity occurred 
of returning the hosjiitality of some of these gentlemen at a dinner party given 
by the deputation at the Hotel de Crillon, where they had the pleasure of meeting 
M. Rabut and j\I. Mesnager (Ingenieurs en Chef des Fonts et Chaussees), M. Michel 
(Ingenieur of the Fort of Honfleur), Professor le Chatelier and M. Feret, who 
are well known in connection with their research work on Portland cement, 
M. Hennebique, M. Coignet, and others. During their stay in Paris the members 
of the deputation were greatly impressed with the very cordial reception that 
they were accorded, and the anxiety on the part of their hosts to give them all 
possible information and facilities for seeing their works. They were also much 
struck by the boldness and originality displayed by the designs of French 
engineers. 



406 



TESTING LABORATORIES 




Testing Laboratories 

for 
Concrete and Cement. 

PART VI. 
i ..-J Hv Cl.C'.ll. II. DtSCH. D.Sc, Ph.D. 

The absence of an official Utoralory demoted to inirestigations "With concrete and cement 
may be said to account in no small degree for the dearth of reliable data as to reinforcea 
concrete as designed and executed in this countrv^ 

Some testing station enfoying official support, or if conducted by some independent 
technical body at least enjoying official recognition, tvould be "very much in place at the 
moment, and it mtght be a matter 'worthy of the attention of the Concrete Institute to 
consider the possibility, and tuays and means of obtaining for the British Empire some 
laboratory of this description* 

We ha've presented particulars of a number of laboratories in the preceding articles, ana 
this article deals luith one conducted as a pri-vate industrial enterprise, but enjoying the 
reputation of absolute reliability, and thus being frequently commissioned to undertake tvork 
for public departments* — ED. 




Of tlic luinierous iin(X)rtaiit testiiii^ laboratories on ihr Coiitiiu-nt, those of Berlin an^J 
Zurich have l)0('n clescrilxHl in former articles of this series. We are now enabled to 
imblish sonic |>ariicLiIars of two national laboratories, situated in Copenhagen and in 
Koine, both of which embrace the testiiiij^ of cement and concrete in their routine. 




mamaammm 



Fi_. 1. Machii 



; for Compression and Bending, of 250 tons Capacity 
Itali.xn State Testing Laboratory. 



CECIL H. DESCH. 



ICQNCBEnE] 



DANISH STATE TESTING LABORATORY. 

An account of the Danish State Testing Laboratory in Copenhagen has been 
published in connection with the recent International meeting in tliat city. It appears 
that the earhest tests of the strength of materials, made with tlie object of controlling 
the processes of construction, are due to an officer of the Swedish armv, Paul W'urlz 
(1612-1676), who was of Danish birth. 

Passing to modern times, we find that as early as 1858 the Danish Corps of 
Engineers began systematic tests of the properties of concrete for embankments and 
fortifications, with the result that concrete was adopted by them as the sole material 
for marine fortifications twenty years before it was empIo\i-d bv military authorities 
in other countries. The Danish State Testing Laboratorv was established in 1896 by 




the Society of Civil Engineers, and in April, 1909, it became a Government institution. 
.\lthough small in comparison with many other testing laboratories, it has already 
proved of great utility both to the State and to the industries of Denmark. 

The equipment includes a 32-ton hydraulic press by Amsler-LafTon, of Schaff- 
hausen, a 50-ton machine for tensile, bending and compression tests, by T. Olsen, of 
Philadelphia, and a 120-ton Brinck and Hiibner hydraulic press, besides smaller 
testing machines. In testing cements, regular use has been made of the accelerated 
test due to Erdmenger, in which both tensile and compressive test-pieces are tested 
after being heated for six hours in a boiler under a pressure of ten atmospheres. This 
test, rarely employed elsewhere, is often prescribed in Danish specifications. Trans- 
verse tests on prisms have been made as at Zurich. Several investigations in 
connection with the laboratory were communicated to the meeting of the International 
-Association, and an account of the recent important tests of the influence of sea- 

408 






TltSTIS'C, LAIiORATURIliS. 



waiir has .ippcircd in t'<)N( ni.tI' am) Consiiuc tionai, liNGlNKKUiNC. Ttsis of (ire- 
rcsisliiiti iiialcri.'ils lia\c \>vi->\ iiiadc, llic bricUs or oilier materials to be Icslod bein{< 
buill up U) form a diambcr, licalctl internally by f^as. 

Tests of many kinds of bricks are made, includinf;^ cement bricks, which have 
attained to some dej^ree of im|x>rtance in Denmark in the last few years. The tests 
include those of resistance to frosi, which, however, cement bricks fjfonerally fail to 
pass. Concrete pipes which are too l.-irge for the testini; m.achine are loaded by means 
of a simple lever arranfjement, capable of testing pipes up to 32-in. diameter. 

Ucsearclu's, which have not yet been completed, have been jiiade in order to deal 
wilh ihe problem of producinif dur.-ible surfaces of coloured cement in the external 
decoration of buildings. The Thorvaldsen Museum in Copenhatren is decorated 
externally in inlaid coloured cements, and the different colours have shown very 
unequ.d (lef;;rees of rf-isl;ince lo ue.ilher, ihe yellow .ire.is in p.irlicul.ir h.ivinf^ suffered 




Fig. 3 Hydraulic Compressor. 
Italian State Testing Lauoratory. 

badly. .Althouj^h means of ]>reventin.tr the formation of fine fissures durintf setting, 
the principal initial cause of deterioration, have not yet Been discovered, progress has 
been made in the choice of durable pigments, capable of resisting the ;ilk.ilinity of the 
cement. A report has also been publi<luxl on the most suitable jxiints for a[)i)lic;ition 
to new- cement surfaces. 

ITALIAN STATE TESTING LABORATORY. 
The Experimental Institute in Ronu' is the central Testing Station of the Italian 
Department of .State railways. It is housed in a large and well-arranged building, 
and is capable of dealing with the w hole of the very great variety of materials required 
by the railways. The laboratories for the testing of cement and concrete, with which 
we are particularly concerned, are large and roomy. The equipment includes an 
.\msler-Laffon machine for compression and bending, of 250 tons capacity, and there- 
fore capable of taking reinforced concrete beams and columns, a tensile testing machine 
of 150 tons, also by .\msler-I,affon, together with a smiilar machine of 30 tons. There 

409 



CECIL H. DESCH. 



[CaNCPETEl 



is also a universal 5(1-1011 macliine by Mohr and Federhoff, of Mannheim, a .s-ton 
machine for tension and bendinjj, and two 50-ton presses for cement cubes, all by 
Amsler-LalTon. All these machines are actuated by a central hydraulic compressor, 
electrically driven, and tr.insmitting' power by compression of olive oil. The ijeneral 
disposition of the larger machines is seen in Figs, i a<nd .', and the compressor in 

Cements are mixed mechanically in a Steinbrijck mixer and rammed automatically. 
Fineness is determined with the aid of Tetniajer mechanical sieves, and .setting time 
both bv the Vicat needle and by Fantini's automatic modification of it. There is also 
an apparatus for measuring' the development of heat during setting. Both the Le 
(^hatelier and the micrometric methods are employed in the detection of expansion. 
The permeabilitv of stone, concrete, etc., is tested in Tetmajer's .apiJaratus, and the 
action of frost bv means of a methvl chloride machine, constructed by Don.ine, of 
Paris, and shown in Fig. 4. 

The chemical laboratories undertake the analysis of cements, sands and numerous 
other materials, and a complete microscopical equii>ment provides for the examination 
of such materials as are capable of being studied by this method, now gaining greater 
importance in respect to cement as well as in respect to metals. 

A large part of the building is given up to the testing of electric motors, telegraphic 
apparatus, and other objects with which we are not directly concerned. Lastly, there 
is a verv complete collection of specimens of constructional materials, with their 
recorded tests, and of models. Large though the Institute is, it delegates a great 
deal of testing to the subsidiary laboratories in Turin, Florence and Palermo. The 
organisation of public testing has been recently referred to in this journal, in a report 
on the steps taken in European countries to ensure uniformity of testing. 

\\\' are indebted to our contemporary, the Iiii;i\i;iirriii Fcrr.iviaiia of Rome for our 




^ 10 



J J. ClON.VlPIK-naNAlJ 
I' V tN(.lNl:.KI^lNt. — 1 



coy CRETE IN FARM liUILDlXGS. 



^ 


Wi- 


•^ 


' < 


h 






CONCRETE AS DISCUSSED 


h 


i; 




AT THE 


P 


1 ' ■'.: 


=^-^=r:^ 


NATIONAL ASSOCIATION 


1 




-: >->sfe^ 


OF CEMENT USERS. U.S.A. 

> , _^ 



The National Association of Cement Users of America held their sixth Annual Convention 
at Chicago in February last* tvhen a number of 'valuable papers and reports "were read. The 
more important of ihesc 'U'tll be published in our Journal. ED. 



THE USE OF CONCRETE IN FARM BUILDINGS 
FROM A SANITARY STANDPOINT. 

By S. CUNNINGHAM. 
'I'lii; irqiiirciinMits for sMiiitary construction of farm IjuiWinj^-s make concrete and cement 
the most useful material for lliwjrs and walls and even for roofs and ceilings when 
ex|)ensc does not prohibit its use. 

Most Hoards of Health which undertaUe (o rej.fulate the production of milU sold 
under their jurisdiction require or advise the use of cement for floors in cow stables 
and specify also that the walls and ceilinj^s must be tijjht, clean, and free from dusl- 
catching surfaces, which evidently sui;>;est the use of cement or hard plaster finishe.s. 
At present, stables are usually built of wood, but concrete in blocks or cast in foritis 
is being used more each year, and there are already a lartje number of barns .scattered 
throutfhout the country which show in a hi}.^hly develo]X'<l way the best uses of 
concrete. The lireproof and permanent qualities of this material are also |X)werful 
inducements towards its use. The ease with which it may be kept clean, the g^ood 
health of the animals stabled therein, and the [xissibility of prixlucintj clean milk with 
a minimum of labour all increase the weight of .argiiment in its beh.ilf. 

/-/oors. — I'or floors, concrete shows practically no wear from ut;e ; it is watertight, 
non-absorbent and .sanitary, and if sufllcient bedding is used it makes a satisfactory 
material for animals to stand and lie upon. When the floor is upon earth fill, it is ad- 
visable to put a layer of sand 6 in. or more thick under it, especially in damp localities, 
and to place under the stalls themselves a waterproofing layer which is easilv made bv 
putting down two or three layers of tar-paper on a base of cement, and brushing it well 
with coal tar pitch. This prevents dampness from drawing up through the concrete and 
makes a warmer floor. Th;' waterproofing should be covered with a thickness of 
concrete and cement surfacing of at least 3 in. for cow stalls and 4 in. for horse 
stalls. It is possible to use less than this for cow stalls (but not advisable in horse 
stalls) by putting down metal lath over the waterproofing, nailing through to the 
concrete beneath to hold the lath firm, then plastering the lath with a heavy coat of 
cement mortar mi.xed i to 2, i-in. lliick, or more. .Ml stall surfaces and passages to 
be used by animals should be left rough, finished with ;i woixlen float, or ;i float covered 
with carpet. 

The feed mangers in front of the cow stalls should be low and of just sufficient 
depth to allow- also of watering the cows. Six inches is deep enough. Watering in 
this way at regular periods has been proved the best for cows. They drink more. 



CEMENT USERS' ASSOCIATION. 



ICQNCBETEJ 



and at more suitable intervals, than when they have water alwavs before ihem in 
individual drinking' pots, which are, besides, very difficult to keep clean. 

The stalls should be made fairly short and should pitch not more than i in. to 
In in. to the gutter. .\11 feed passages, mangers and gutters should have a smooth 
hard trowelled finish, which is easier to keep clean than a float finish. Horse stall 
floors should be treated as for cow stalls. They should pitch about 2 in. toward the 
gutter. The gutter in this case should be very shallow, not over 15 in. deep, 16 in. 
wide, and uncovered. There will be more wear on hor^e stall floors, so they should 
be laid more carefully with this in view. 

Where the floors join the walls, and, in f.ict, all interior angles in the stable, should 
be covered or rounded on a 3-in. radius to i>revent corners for the collection of dirt — a 
small detail, but one th.it makes a great difference in the cleanliness of a stable. 

Walls. — Concrete in many fomis has been used for walls. The object to be attained 
is a hard, smooth wall surface insulated as well as possible from changes of external 
temperature. It is, of course, not difficult to prevent moisture coming- throug^h from 
the outside, but condensation of moisture inside is more difficult to avoid. Concrete 
blocks with air spaces, cored, reinforced walls, and soHd walls, furred with wood or 
metal and finished with plaster on metal lath, or lined with plastered partition tile 
or concrete blocks with a space between the two walls, are methods used for insulation. 
Dampness in a stable is very often a sign of poor ventilation. If the air space in the 
walls is filled with chopped straw, sawdust, or planer chips, the insulation is improved. 

Ventilation. — This subject of ventilation is very important, and definite means 
should be provided to enstire a pr<)]>er circulation of air. The old farm buildings, which 
were scarcelv more than rough sheds, were full of cracks through which the air could 
pass. Modern concrete barns leave nu such chances for haphazard ventilation, and with 
fortv cows in a barn of 20,000 cu. ft. ca|)acity. each cow requiring five or six times the 
amiiunt of air necessarv for a man, the ventilation must be positive and adequate to make 
the conditions healthful. There are several good systems of natural ventilation, and no 
barn should be constructed without one of these, or other proper means to supply fresh 
air. In northern climates the barns should be made small, about 500 or 600 cu. ft. 
capacity per animal is about rigfht. .Such a building is easier to keep warm, and yet 
is large enough to allow of proper ventilation without causing severe draughts. The 
ventilating flues may be built of concrete, tall enough to act on the principle of a 
chimney, and to cause circulation bv difference in weight of the column of warm air 
within and cold air outside. 

For piggeries, the use of cement in construction is as advisable as for stables. 
Thev are much more llkelv to be neglected and allowed to become foul, and a cement 
finish is so easily washed down that there is no excuse for any such condition. Pi.gs 
are liable to contagious diseases, and a building th.'it can be hosed out and disinfected, 
and having no absorbent materials or cracks to harbour bacteria, can be used again 
w ith no dangler of the infection spreading. This applies as well to cow stables. 

Silos. — .\lmost all large milk farms depend in a great degree on ensilage for feed. 
.\ cement silo is equal to the best that can be built for storing ensilage. The proper 
preservation of ensilage depends on keeping it packed tight to exclude the air, with 
smooth walls, so that as the ensilage settles it doos not loosen at the walls to admit 
air there. Structurally, cement silos are practicaily everlasting. The acids existing 
in the fermented juice of the corn attack the surface to a very slight degree only, and 
cement walls, either solid or cored, prevent the freezing of ensilage better than a 
wooden stave silo — the form most commonly used. The freezing not only spoils that 
part of the ensilage Iving within a few inches of the wall, but by causing the frozen 
ensilage to cling to the wall, the even settlement is interfered with and part of the 
rest spoiled by the admission of air. 

412 



y.-SMNLVyiNo^ LAYING CONCRETE UNDER WATER. 

Poultry Houses. For ixniltry houses, concrete makes a warm, lif^hl buiklins^^ that 
will ixiluiic lal^ aiul other animals preyinf^ on chickens, and that can be kept clean to 
ihe picvcnlion of vermin. The ntH)rs in laying-house pens should be made 6 in. below 
(he levels of the door sills and filled with cut straw or gravel for scratching. This can 
be renewed as often as necessary to keep them clean. 

Where manure is stored and not spread on the fields as soon as produced, a 
light pit, covered or uncovcre<i, is necessary, and concrete offers an excellent material 
of which to construct such pits. The floors may be pitched to a sump pit in one 
corner and the liquid pum|)e<l out and applieil to the fields, using a sprinkling cast tor 
this purpose. 

Ihe produclion of clean milk requires the Ix'st sanitary conditions in the buildings 
in which the milk is handled, as well as in the cow stable where it is produced. The 
extensive use of concrete floors and smooth plastered walls with coves in all angles 
will m.ike such a dairy easy to keep clean, but offers no particul.ir requiremenls 
in the way of sanitary design. 

For greenhouses, hol-beds, and wherever wood in contact with e.irth has been 
found to rot out, concrete has been substituted with the expected advantages. T.iblcs 
in greenhouses can be easily designed and built of it, making them permanent and 
avoiding a large item of ex|X'nse in renewals. No objection has been discovered to 
its use in this way from any unfavourable action on the plant life. In fact, it forms 
a better protection th.nn wood from possible variations of temperature. 

The fact that concrete can be kept clean more easily than any other m.ilerial in 
common use is its greatest recommendation for its use in farm buildings. The 
realisation that health to a very great degree depends on cleanliness is as true for 
farm stock as it is for mankind. Good labouring help is difficult to obtain on most 
f.irms, and anything that contributes to tlie reduction of labour necessarv to keep 
the surroundings clean is bound to grow rapidly in favour on that score alone, 
especially since no v.ilid objections can be substantiated to its use in connection with 
stock or farm ]>roducls. 



LAYING CONCRETE UNDER WATER. 
DETROIT RIVER TUNNEL. 

By OLAF HOFF. Consulting Engineer. New York. 

\ AKiOL's expedients and devices have been adopted for solving the problem of depositing 
concrete under water, the principal ones being the use of bags, drop-bottom buckets 
and tremies, all subjeit tu objections [H'culiar to each. 

Various Methods of Laying Concrete under Wa/er. — Laying concrete under 
water by means of bags involves the use of divers in placing the bags, and is, accord- 
ingly, cumbersome, slow, and expensive; the results are not wholly satisfactory and the 
method should be classed as obsolete. 

Neither is the use of drop-bottom buckets all that could be desired ; even with the 
greatest care it is not possible to prevent the mass from dropping a short distance 
through the water, which, thus set in motion, has a tendency to remove the cement 
from the aggregate and produce a lean concrete in spots, where a uniform and homo- 
geneous structure is the ideal sought for. Irregular cleavage lines in the concrete are 
likely to occur, which objection is also applicable to the use of bags. 

The depositing of concrete in water by means of tremies has heretofore presented 
ditificulties which have not always produced satisfactory results. A tremie is nothing 
more or less than a long tube reaching from the place where the concrete is to be 
deposited to the surface of the water above, its upper end being provided with a hopper 
for receiving the mixture; as fast as the concrete escajjes at the lower end of the tube 
it is replenished at the ujiper end, thus flowing in a continuous stream. 

4«3 



CEMENT USERS' ASSOCIATION. [CQNCBETE] 

Theoretically, this is the ideal way i>f laying concrete under water, but when 
reduced to practice the object has not proved so easy of accomplishment. The difficulty 
has. principally been to control the flow of the concrete through the tube and prevent the 
water from the outside rushing" into the tube from below, thus washing the concrete 
and separating the cement from the aggregate, losing the charge; the concrete would 
be liable to run out either too fast or too slow. (ienerally the concrete has been 
deposited in layers of various thicknesses, governed by the position of the mouth of the 
tremie with reference to that of the layers below. This also, of necessity, results in a 
certain amount of motion of the concrete through the water, with attending loss of 
cement. 

These difficulties were successfully overcojne in the construction of the Detroit 
River Tunnel, more than one hundred thousand cubic yards of concrete having been 
deposited in water by means of tremies, the operation extending over a ]X-rii>d of part 
of three seasons, igoy, igo8, and igoq. 

In order to describe the methods used and convey a correct understanding of same, 
it will first be necessary to give a short description of the tunnel itself and more par- 
ticularly the subaqueous part of same. 

Detroit River Tunnel. — This tunnel is of double track, built for the use of the 

New York Central system of railroad lines, passing under the Detroit River and con- 
necting the city of Detroit, .Mich., with the town of Windsor, Canada. It is built as 
two separate tubes with a centre wall between each with an overhead clearance of i8 ft. 
above top of rail, and a length of 8,360 ft. from portal to portal. It consists of three 
sections, the westerly approach on the American side, 2,135 f'- 'ong, the section under 
the Detroit River pro|x-r, or subaqueous section, 2,625 ft. U>ng, and the easterly 
approach tunnel on the Canadian side, 3,600 ft. long. 

The westerly approach tunnel and adjoining end of the subaqueous section is on a 
2 ])er cent, gradient and the easterly approach tunnel on a li per cent, gradient. The 
subaqueous sectipn has a level grade of some 1,000 ft. merging into the approaching 
gradients through long vertical curves at either end. It also has a short horizontal 
curve of two degrees curvature at the westerly end. The pKjrtals are approached 
through long open cuts at both ends of the tunnel. 

The approach tunnels on both sides of the river were driven through a formation 
of plastic blue clav bv means of shields. The same clay formation extends across the 
river and overlies bed rock which i^ found at a depth i>f some 10 ft. to 30 ft. below the 
tunnel structure. 

The subaqueous section was built on a unique and novel plan never heretofore 
used, which proved highly successful both as to cost, speed of construction and safety. 
It consisted in excavating a trench in the bottom of the river, of the required width 
and depth, into which ste-el tubes were sunk ; these were thereupon encased in concrete 
laid under water, pumped out and then lined with concrete on the inside. The whole 
operation proved to be very simple and easy of e.xecution. 

The top of the tunnel structure generally follows the bottom of the river ; at the 
middle it even projects a few feet above the bottom ; at the dee|>est part it is 41 ft. 9 in. 
below the surface. The bottom of the structure at this point is about 74 ft. below the 
surface of the river. 

The excavation of the trench was done with an ordinary clam shell dredge, well 
in advance of the sinking of the tubes. The tubes were circular in form, with a 
diameter of 23 ft. 4 in., and were arranged and sunk in pairs, one tube for each track; 
thev were built of |-in. steel plates. They were spaced 3 ft. apart between the shells 
and reinforced on the outside by a series of transv-erse steel partitions or diaphragms, 
12 ft. apart. These diaphragms extended all around the tubes and were approximatelv 
of rectangular shape with an extreme depth of 30 ft. 4 in. and extreme width of 55 ft. 
8 in. ; thus extending beyond the steel shell 3 ft. at the bottom, 3 ft. on the sides, and 
4 ft. on the top of the tubes. They were strengthened by means of double angle irons 
riveted along the edges; wooden sheathing running lengthwise of the tubes was 
bolted along the vertical edges of th-? diaphragms. The tubes were built in lengths of 
262 ft. 6 in. and were provided with temporary wooden bulk-heads at the ends so that 
thev would float when launched. 

For the purpose of sinking the tubes they were equip|>ed with four buoyancy 
c\linders attached on top, which enabled the tubes, when filled with water, to be 

41 + 



i&^wSIIS no^ laying concrete under water. 

and ods Into th^^.l! "'"•"" '''' "^' '"'' ■•""' ''"""'"■ t^"' ^^'ith enclosed sides 

i.o,„i,«'Sr ir^:-:; ;;;!,;;;r*^:i sx ':„;'.:;;'»-, S,';3;;r^e"S 
£S,r •" ■' "■ "■ ' "' -"•■"'""" '"<■ '"'-•>■ ""■?"'«"■.;;■,' ;;;rl'';:.."',';;-,;r,',.; 

gliiiJiiEiiigils 
iPiiliiifiill 

mrnmmmmM 

chati, °"Z,i:'''-l!'^-! ;,';^ P-P- ■—'J^.f ,n.ve, andTand"c;:,^d^be d^aTntt^t: 
f 'Cne ncK^K ThJ , T T""' ''""""f ^""''"^ ^« ^^"'^ •'' sufficient quantity of cement 
Xed toCmixeTi: ™ ''"'' "•'•^ ^'^'^ '"^■■'^'^ <^" '•''^ "'^-' f-"-vhich water w^s 

discl7ii'eTuo'''!.1fT'^*"'? T^P''''''^^ ^'''^'^">' °" 'he deck and xvhen tilted would 
d..charj^e ,nto self-dumpm^ buckets, placed in the liull of the scow directly in front of 



4' 5 



CEMENT USERS' ASSOCIATION. 



[CDNCBETEJ 



the mixers; these buckets could be hoisted up to any point where the receivin;,' lioppers 
of the tremies might happen to be located and discharge their contents into same. 

The total amount of concrete in one pocket was about 342 cu. yds., of which 
approximately one-half had to be deposited through the centre tremie and one-fourth 
through each of the side tremies. 

Each tremie consisted of a 12-in. diameter spiral riveted steel pipe of Xo. 10 metal, 
80 ft. long, made in 20 ft. lengths provided with external flanges for bolting up. The 
upf>er end of the tremie pipe was suspended from a frame, to which was attached a 
hopper for charging the tremie, the hoppers with frames running between guides 
attached to the tront of the before-mentioned towers. The tremie pipes, hoppers and 
all could be raised and lowered by means of steel hoisting ropes leading over sheaves 
at the top of the scow. The buckets in the hold of the scow, upon receiving a charge 
from the concrete mixers, were hoisted up inside the towers until they reached the 
tremie hoppers, which would engage them and trip them forward, discharging their 
contents into the hoppers ; then they would reverse and go down to their place in the 
hold of the scow. These buckets ran between guides located inside the towers im- 
mediately in the rear of the guides of the tremie hoppers. The concrete, in passing 
from a mixer into the bucket, would discharge over an apron which the bucket would 
trip forward every time it descended and trip back out of the way when hoisted up. 
The tremie hoppers were provided with a small platform on the outside and a railing 
around same where a man could stand and watch tlie concrete in the tremie, whether 
it was rimning out too fast or too slow, nnd give signals accordingly to the engineer 
who ran the corresponding engine. 

The working force for oi>erating the tremie scow when the process of concreting 
was going on was 32 men on an average. 

Method of Working the Tremie Scow. — The tremie scow was anchored across 
the tunnel tulies in tlie trench so that the tremies when lowered into place would come in 
the middle of the pcx-kel, as already stated, one tremie between the tubes and one on the 
outside of each tube between the steel shell and the sheathing. The spuds were then 
lowered to the bottom and forced down sufficiently to take up a considerable load from 
the scow and prevent any rocking motions. The three tremie pi])es were lowered into 
position until their lower ends rested on the bottom of the trench ; the water inside of 
the tremie tubes would, of course, be at the same level with the water outside. Mean- 
while, the boat loaded with gravel would be placed alongside the tremie scow on the 
opposite side. The gravel with its mixture of sand would then be unloaded by means 
of the clam shells and derricks, and drop]>ed into the hoppers previously described, 
falling over the inclined screens, the sand and gravel shooting off into their respective 
bins, from which they would, in turn, be drawn as required into the super hoppers of 
the concrete mi.xers, cement added, and the charge shot into the mixers, where the 
necessary water was added in the usual way. 

.'\ wadding of cement sacks was at first placed in each tremie on top of the water 
to prevent the concrete from dropping through while tilling' the pipe. .\ batch of 
concrete was discharged from the mixer into the bucket in the hold of the scow and 
hoisted up until a projecting arm on the receiving hopper of the tremie would cause 
the bucket to tilt forward and discharge the contents into the tremie hopper and on top 
of the wadding, the bucket immediately returning to its original place to receive a new- 
charge, alreadv in the jirocess of mixing. When this hoppxer was about half filled, the 
tremie and hopper would be raised a trifle, permitting the water in the tremie to escape 
at the bottom as the weight of the concrete pushed the wadding downwards through the 
pipe. Meanwhile fresh batches of concrete were being dumped into the tremie hoppers. 
In this manner the tremie was filled with concrete until the wadding reached the 
bottom and the concrete commenced to run out of the pipes. As fast as the concrete 
ran out at the lower end of the tremie pipe, fresh concrete would be added to the upper 
end of same, this process going on until the whole pocket was filled. 

This wadding of cement bags was used only at the beginning of the work. It was 
soon found that one or two verv drv batches of concrete would serve the same purpose, 
and this was used practically throughout the work in charging the tremie at the 
beginning of an operation. 

The concrete, except as noted in charging the tremies, was mixed verv wet, much 
more so than would be permissible in concrete deposited in the air. Xo <lirficulty, how- 
ever, was experienced on this account. 

416 



M 



.';S:'S!?V'JJ2^ii1 LAYING CONCRETE UNDER WATER. 



NdlNbt.KINr. ~- 



It should be parlicularly noted that the inouih of the treinie was always buried in 
the concrete from 2 ft. to 5 ft., forniinjj; an el'fective seal which at all times |>revented the 
iiul-.idc water from forcing itself into the tremie. 1 1 was the duty of the inspector on 
ihr pLidonn ol tin- ireniie hopper to ;ilways be on the looU-oul that the iremie was full 
111 coiurcii'. n ilii' I'nicrete showed a tendency to run out too fast he would sijifnal the 
hoislinj;' ent^iiiccr to lower ilic Iremie and thus choke off the How; if the concrete did not 
How fast enou};li he would iMxler the tremie raised until the concrete would How mor<' 
rapidly. 

In deposilini.'; the concrete divers were em])loyed for inspectini,' the ])ro{jfress of the 
work, and report when a pocket was completed. 

The time required for fillinif one |)t>cket usually ran from 4 to 7 hours. The 
lartfest amount of concrete placed by the tremie scow jxir day was three pockets or 
1,025 cu. yds., workinfj 16 hours. This includes the time required for replacing th- 
t^ravel t)oats alonffside the trcinie scow. 

The leiifjth of time of mixinj^' a b.itch was usually from 2 to \ minutes. The time 
for the concrete to reach its place of deposit from the mixer would, of course, vary 
,y;re;itly, but the averat^e time w;is prob.ibly about S minutes, with a minimum of 5 
minutes and a maximimi of 15. The velocity of the flow of concrete in the tremi<-s 
would averaije from 14 ft. to 15 ft. per minute, the extremes probably running from 
7 ft. to 25 ft. " 

When the work first commenced the side trcmies were made of [o-m. ])ii)e, as 
aj,'ainst 12-in. for the centre tremie. This was done because the amount of Concn-te 
passinjj through each of the side tremies was a])proxiniately only half of that of the 
centre tremie. .\fter the first section h.ad been completed all three tremies were made 
12 in. in di.ameter fi>r the sake of convenience, as by that lime it was found that the flow 
of the concrete could be absolutely regulated to suit the requirements. 

The wear .and tear of the tremie pi]>es proved very insignificant, the full set of 
Iri'inies having been renewed only once. 

Mixture of the Concrete, — The concrete w.as mixed in the following proportions : 
In the bottom of tb.e trench below the diaphragms it consisted of i part of cement to 
4 parts of sand and 8 parts of gravel. The concrete in the pockets consisted of i part 
of cement to 3 parts of sand and 6 parts of gravel. Gravel of small walnut size was 
used in preference to crushed stone as it was thought it woul<J cause the concrete to 
llow' easier in the tremies; besides gravel makes a denser concrete than crushe^d stone. 

In some of the pix;kets at the joints between two sections the concrete was made in 
the jjroportion of i part of cement to 2 of sand and 4 of gravel. The reason for making 
the concrete in these pockets richer was simply a matter of precaution, taken to insure 
a tight joint, the steel work not filling together as closely as intended. When the tubes 
were pumped out no water came through these joints, showing that the 1:2:4 con- 
crete was practically impervious to water, although subject to a hydrostatic pressure of 
al>out 25 lb. to the sq. in. 

For the pur]X)se of determining the quality of the concrete, 6-in. cores were taken 
out by means of a Davis Calyx drill for the full height of the centre wall between the 
steel tubes. These cores show a rem.nrk.able degree of uniformity of the concrete and 
of high quality both .as to densily and strength; in fact, a l>etter grade of concrete was 
obtained than would be possible in the o|}en air. It should be noted in this connection 
that this concrete was compressed and set up under a hydrostatic pressure of from i() lb. 
to 30 lb. per sq. in., at the top and the bottom of a pocket respectively. 

The crushing strength of this concrete, when i year old, ran from about 2,800 lb. 
per sq. in. minimum, to 4.000 lb. per sq. in. m.aximuni, for a mixture 1:3:6 according 
to tests made ujion cores taken fro:n the centr<- w;>ll. 

Setting Time. — A word should be said with respect to the time of setting or 
hardening of the concrete; that is, to be sure, a debatable subject. However, the 
consensus of opinion among the engineers connected with the work, including the 
writer, based ujwn such tests as could be made by divers, seemed to be that the initial 
set was acquired in about 10 hours after the concrete was deposited, and the final set 
in 20 hours; after 40 hours the concrete was very hard, so that it would ring when 
struck with an iron bar. 

Regarding the matter of laitance, hardly any was observed that would affect the 
quality of the work; this might be ex|)ected considering the manner in which this 

n 2 417 



CEMENT USERS' ASSOCIATION. [JJONCUFJEl 

concrete was deposited, whereby the i;reat mass of it would never come in contact with 
the water at all. 

It may not be amiss to point out the three essential elements that contributed to the 
successful results in depositiny^ the subaqueous concrete of the Detroit River Tunnel ; 
they are as follows : 

First, dividint; the exterior of the tunnel tubes, by means of the lonijjiiudinal 
sheathintf and the diaphragms, into compartments or ]X)ckets. This prcKluced still 
water, which is absolutely essential for layinsi; concrete under water, and permitted 
the filling of one pocket at a time with one monolithic mass of concrete. This 
arrangement further limited the lateral flow of the concrete, as it emerged from the 
tremie, to the confine of the pocket and reduced the washing out of cement by the 
water to an absolute minimum, in fact the loss of cement appeared to be negligible. 

Second, the use of an equipment complete in every detail and equal to any 
demand made upon it, more especially an active or quick-acting rig for handling the 
tremie pi|3es promptly as occasion required. 

Third, mixing the concrete so wet that it would readily How in the tremies, and 
the flow controlled by keeping the mouth of the tremie ,it all times buried in the 
concrete at a sufficient depth thereby at the same time kee])ing it sealed and prevent- 
ing the water from rushing in from the outside. 

The demonstration of these highly successful results on such a large scale suggests 
possibilities of the application of this method to various kinds of engineering works, 
other than subaqueous tvmnels. It may perha]js be permissible to venture a few 
suggestions of such applications. 

Structures now frequently built of cyclopean concrete blocks, such as dock and 
quay walls, breakwaters, etc., could in many instances be built in situ, by using 
steel forms constructed on the compartment or pocket principle, which would result 
in obtaining monolithic and massive blocks, or sections of structure of far greater 
/iiagnitude, than otherwise possible. The steel forms could be built extremely light 
and left in place, or heavier and detachable to permit their being used over again, as 
economy and expediency might dictate. If piles were required for providing a proper 
foundation thev could be driven after the excavation was done to the required level, the 
forms set over them and then embedding them in concrete. 

Similarly, dry docks, lighthouse foundations and bridge piers could be constructed, 
alw.ays, of course, depending upon local conditions and circumstances as to the 
applicability of the method. 



DOCK WORKS AT IPSWICH. 







:.^0j!mm 



REINFORCED CONCRETE 
DOCK WORKS AT IPSWICH. 



our readers, giving JS it does pjrticuUrs of the reinforced con 
djte to be able to shew vteius of Itie finished structure. ~-ED. 



Do^ks should i-e of Interest to 
:rete ijujy. We hope at a later 



A NOTABLE improvement now in progress for the Ipswich Dock Commis- 
sioners inchides the reconstruction of the narrow quay in front of the public 
warehouse and an extension bringing the total length of the new quay up to 
about 323 ft. long from end to end. 

The original works, constructed in 1880, provided merely a timber quay. 
II ft. wide by 170 ft. long, in front of the warehouse, and as the natural slope of 
the dock bottom could not be interfered with for fear of impairing the founda- 
tions of both structures, the depth alongside was only 8 ft. 6 in., making it 
impossible for vessels to discharge cargo directly upon the quay. 

In addition to the necessity of bringing the deej) water of the dock nearer 
to the warehouse, the dilapidated condition of the timber framed wharf rendered 
the work of reconstruction unavoidable. 

The scheme prejiared by Mr. Thomas Miller. M.Inst.C.E., the engineer to 
the Dock Conmiissioners. provides for a reint\)rccd concrete deepwater quay 




419 



REINFORCED CONCRETE. 



ICQNCBETFJ 




27 ft. wide throughuut. with 
accommodation for one railway 
track connected in two directions 
with existing lines of rails from 
the New Cut East and the New 
South - East deepwater quay. 
Thus the dock authorities will 
secure safe berths for the long 
and deep draught vessels fre- 
quenting the port, as well as 
means of dealing more expedi- 
tiously with cargo, and will have 
excellent means of transport to 
and from the public warehouse 
and other buildings behind the 
quay. 

After the consideration of 
tenders under various forms of 
reinforced concrete, the Com- 
missioners accepted one in accor- 
dance w4th the Hennebique 
system of reinforced concrete, 
submitted by Messrs. A. Jackaman 
& Son, of Slough, by whom the 
recent extension of Parkeston 
Quay was carried out for the 
Great Eastern Railway Company. 

Tig. 2 is a general plan 
showing the extent and main 
dimensions of the new quay and 
the positions of the public ware- 
house and coal storage shed. 
Besides the construction of the 
quay, the works include some 
interesting examples of under- 
pinning and anchorage, the latter 
being for the purpose of enabling 
the new structure to withstand 
the outward pressure of earth 
and filling employed for reclama- 
tion purposes. Another detail 
of special interest is the turn- 
table pit, near one end of the coal 
storage shed. 

Bv the general plan it may 



E 



CONSTBUITIONAIJ 
ENGINILEBING — J 



DOCK WORKS AT IPSWICH. 




be seen that the quay 
comprises 32 bays foun- 
defl upon reinforced con- 
crete piles spaced 10 ft. 
apart longitudinally, ex- 
cept at the further end 
where the distance is loi 
ft., and at the old lock 
end where the decking 
beams are housed into 
and supported by a 
masonry wing wall 3 ft. 
thick. 

.\ more complete idea 
of the design is furnished 
by Fia. 4, which gives a 
section in front of the 
warehouse. The founda- 
tion piles in the front 
row are 14 in. by 18 in., 
and those in the back 
and intermediate rows 
14 in. square, driven into 
the gravel slope of the 
dock to the depth neces- 
sary for stability and for 
resistance equal to the 
load of 30 tons, due to 
the rolling load of a 
27-ton shunting engine 
and the distributed super- 
load of 2i cwt. per sq. 
ft. on the decking. 

Between the founda- 
tion piles of the middle 
row sheet piles are driven 
and keyed up with 
cement grout, thus form- 
ing a continuous dia- 
phragm from end to end 
of the wharf, servdng the 
purpose of a retaining 
wall lor filling deposited 



REINFORCED CONCRETE. 



[CDNCBETB 




+ 22 



r»,CONMPIIlTIONALl 
K^ ENdlNhtKINC. ~-.\ 



DOCK WORKS AT IPSWICH. 




423 



REINFORCED CONCRETE. 



ICDNCBET EJ 




4Z4 



[A-KNorN^S!^^] /)OCA' WORKS AT II'SWICH. 

on the landward sidu. and iiiakiiit; impossible any ])eiiclration of water from 
tlip dock. 

The main piles are continued upward in the form of columns securely braced 
l)y longitudinal vvallings and transverse members which, together with the deck 
beams, constitute a series of rigid frames, all in monolithic connection, and 
further stiffened by the continuous slab joining u|i the longitudinal and trans- 
verse beams. 

The decking projects 5 ft. beyond the tiack row of piles, this portion being 
capable of acting as a cantilever, although supported in front of the warehouse by 
the concrete foimdation wall show^n in the section. Elsewhere the projection is 
supported entirely by the cantilevers. Thanks to the depth to which the main 
piles are driven into the gravel, the rigidity of the framed structure, and the 
securely anchored ties before mentioned, the new c]uay has enabled the dock 
engineer to provide for dredging away material to the depth of about 6 ft., so as 
to give about 21 ft. of water alongside. 

The first and most important operation for attention by the contractors 
was that of underpinning the front wall of the jniblic warehouse, with the frontage 
of 121 ft. to the dock. In performing this work the whole of the timber platform, 
beams, wallings. and other parts of the old wharf had to be removed, part at a 
time, so as to give access to the warehouse foundations. These were supported 
by 12 in. square timber piles spaced 10 ft. apart with 10 in. square intermediate 
piles also of timber. The 12-in. piles carried the footings of steel stanchions, 
each bearing the load of 15 tons due to the upper floor and roof of the building, 
and they were tied back by chains attached to concrete anchor blocks. 

The underpinning works included the removal of a timber sill beneath the 
stanchions, cutting away the decayed upper part of the 'piles, building a plain 
concrete wall embedding the sound part of the piles, and carrying up reinforced 
concrete foundation columns from the top of the wall, just below quay level, to 
the level of the warehouse floor. A section of the wall and columns may be 
seen at the left hand of Fig. 4, which also shows the main retaining w-all and part 
of the warehouse floor. The reinforced concrete foundation columns are 12 in. 
square, reinforced by four longitudinal bars with transverse links 6 in. apart, 
each column being provided with a bracket, as shown, for supporting the grooved 
rails upon which run the sliding doors along the front of the warehouse. 

After the execution of the land ties across the public warehouse had made 
the supporting piles of the building perfectly safe, the piles close along the front 
of the warehouse were driven, the vibration from which caused no injury to the 
warehouse structure. The average length of the piles was about 30 ft., the 
reinforcement of these members including four longitudinal steel bars braced by 
transverse links at short intervals apart. 

Considerable difficulty was experienced in driving the piles to the required 
depth through the gravel slope which overlies a compact bed of chalk and clay, 
forming with variations of level and solidity the bed of the dock, but by con- 
tinued driving the piles were finally sunk, some of them having received as many 
as 2,000 blows from a 2-ton monkey. This clearly demonstrated the endurance 
of the piles and the efficiency of the reinforcement in enabling the concrete to 
withstand heavy impact, and the consequent bursting strains thereby developed. 

425 



REINFORCED CONCRETE. [CQNCBET EJ 

By lowering the water level of the dock some 3 ft., the piles were drn'en 
with the head projecting about 4 ft. at the distance of about 6 ft. below the future 
surface of the new quay. The heads were then trimmed off level, and the con- 
crete stripped away to permit the reinforcing bars of the reinforced concrete 
columns to be lashed to the bars projecting from the piles. This arrangement 
is illustrated in Fig. 4. 

The sheet piles driven along the middle line of the quay measure 10 in. 
thick by 17 in. wide by 20 ft. long, each being moulded with a semi-cylindrical 
groove at each side forming half of the cylindrical hole, afterwards filled by a 
key of cement grout. The sheeting was completed by a continuous capping of 
reinforced concrete 22 in. wide by 12 in. deep, with angle brackets filling the 
angles at the junction of the capping and piles. 




The front decking beams are continued up 12 in. above the slab, with the 
object of providing a curb for the road material, which is paved between the 
railway metals with wood blocks and the remainder of the surface with macadam. 

Cast-iron mooring bollards and timber fenders for the protection of ships 
complete the equipment of the quay front. Fig. 4 shows part of one of the 
reinforced concrete ties, 8 in. square, by which the quay is held back to the land, 
details of the connections at Z and Y also being given in this illustration. The bars 
passing through the diagonal braces, C, are bent round li in. diameter pins and 
bound with steel wire, the I'einforcement of the ties consisting of two li in. 
diameter bars similarly treated. 

Fig. 4 also gives a section through the warehouse floor showing a 
complete set of ties. 

426 



DUCK WORKS AT IPSWICH. 



Boyonci the warehouse the himl-tie anchors are laid at a distance of between 
30 ft. and 35 ft. from the new front hne of the quay, the anchors consisting of 
concrete blocks buried deep underground. The maximum strain upon each tie 
is estimated at 18 tons. The anchor blocks measure about 5 ft. by 4 ft. by 
2 ft. () in., the safe horizontal resistance of the soil being estimated at i ton ])er 
sq. ft. 

/•/i,'. _; gi\'es longitudinal and transverse sections of the turn-table pit of 15 ft. 
diameter, carried by the foundation piles of the quay with aid from two e.xtra 
])iles driven behind that structure. This pit demonstrates the capacity of rein- 
forced concrete for the support of heavy machinery without perceptible vibration, 
a point which, in fact, is also evidenced by the whole of the quay here described. 

The details of the reinforced concrete work were prepared by Messrs. I.. G. 
Mnuciiel & Partners, of 38 Victoria Street, S.W. 



427 



SOCIETY OF ARCHITECTS. 




IBIMIMI 



RECENT VIEWS ON 
CONCRETE AND REIN. 
FORCED CONCRETE. 



SOME PAPERS & DISCUSSIONS. 




// IS our intention to publish the Papers JnJ Discussions presented before Technic 
Societies on matters relating to Concret' ^nd Reinforced Concrete in a concise form, ar, 
in such a manner as to be easily available for reference purposes* 

The method 'we are adopting, of dii'idmg the subjects into sections, is, ive belicvct 
neti} departure, — ED, 



THE SOCIETY OF ARCHITECTS. 

CONSTRUCTIONAL STEELWORK. 

By S. BYLANDER. 
.Mr. S. Bylander delivered a paper on " Constructional Steelwork " before the Society oj Architects in 
April last, at which Mr. Percy B. Tubbs, F.R.I.B.A., presided. The lecture was illustrated bv a number of 
lantern slides and diagrams. The paper is a very interesting one atid we are publishing a lengthy summary. 

Planning and Designing. — As the sizes of the buildini^s were increased and 
fiiepioof construction adopted, steel construction could be used with advantage. Heavy 
brick walls were substituted with steel stanchions, and rolled steel beams used instead 
of wooden joists, thereby savinf:^ rentable space, and bv the use of fireproof floors the 
danger of ruinous fire materially reduced. When steelwork constituted the skeleton 
of the structure, it was obvious that the application of this material should be given 
careful attention. The architect must, therefore, make himself well acquainted 
with the principles of steel construction or be in frequent consultation with an 
engineer competent in steelwork design. Economv was the essential thing to aim 
at; consistent, of course, with suitable planning and good architecture. 

Factor of Safety. — The first consideration the desig^ner had to take into account 
was the factor of safety and the loads which should be used in the calculations for the 
different members. If a specification required that the steelwork should be designed 
for a factor of safety of four, this did not necessarily mean that every member was 
four times as strong as that required to carry the s|)ecified load. Often a structure 
could not carry more than twice the s]>ecified load on account of imperfect loading, 
material and workmanship, although it was designed for a factor of safety of four. The 
factor of safety was intended to cover unknown quantities which were not considered in 
the calculations. Good practice w-as to use a safe stress for steel equal to one-quarter 
of the ultimate strength of the material, or seven and a half tons per sq. in., if the 
ultimate strength of the material was 30 tons per sq. in. .'\s the elastic limit of medium 
steel was about 15 tons per sq. in., the actual factor of safety would be two. 

Loads. — The actual live load was not used in the calculations, but the corre- 
sponding dead load which would cause the same stress in the steel as the actual live 
load. This dead load was usually referred to as " superimposed load," and varied 
from 70 lb. to 120 lb. per sq. ft. for apartment houses, hotels, and office buildings, and 
from 150 lb. to 400 lb. per sq. ft. for warehouses and factories. To the above loads 
should be added the weight of the floor itself (including steel girders and beams), 
which was about 100 lb. per sq. ft. for an average concrete floor. The dead load of 
floor must be carefully calculated in each particular case. 

Use of Steel in Buildings. — Steel was used in buildings where the design did 
not permit of the use of only brick and stone work on account of large rooms, great 



428 



>t.N(llNt.LI;IN(. —J 



CONSTRUCTIONAL STEELWORK. 



loads, architectural features or planninij requirements. It was used by reason of 
economy where it was found to be cheajjer than other materials, or where the lloor 
space saved by usinjj steel columns instead of bricU wall or piers more than compen- 
sated for the extra cost of steel compared with the co>t of brick. Steel beams and 
concrete were substituted for wooden joist lloors and roofs in order to obtain a more 
lire])roof construction, often to a considerable increase in the first cost of the building, 
hut the firejiroof buildintj was more profitable to the owner than the old \\o(Klen con- 
struction when the reduce-d insurance premiums ;(nd the incre.ased ri<j;idily and 
stability were taken into consideration. 

In addition to the before-mentioned reasons for usini,' steel in buildini;s, there were 
others more or less im[X)rtant accordinij to conditions :)r circumstances : rapidity of 
construction ; possibility of changing^ the arrangement of rtMims after the carcase of the 
building is completed; increased stability and rigidity; and uniform distribution of 
loads on found.ations to prevent unequ.il sottli-menl. 

Difference between Brick and Steel Construction.— 'I'he setting out of a brick 
building need not Ik- very .lec-urali' .is to <lim<-.,si()ns. The builders could set out the 
walls and foundations to the architect's plans and elevation dr.iwn correct to scale, but 
not necessarily dimensioned. The accurate dimensions of the site were often not ascer- 
tained before the old building was taken down, ;mtl the l)uilder readv to start work 
building the walls. 

In the case of a steel structure, however, it was most essenli.d th.it the dr.iwings 
were completely worked out beforehand, and all details made. 

Ventilation, heating, drainage, lighting arrangements, etc., should Ix- set out 
beforeli.ind, and the general lay-out and steed plans m;ide to suit the different require- 
ments. 

Economy. — Hy the use of steel the rental floor space was increased considerablv ; 
it also |>ermitted the use of large spans and less pillars, iherebv enabling the future 
tenants to arrange the rooms according to their requirements. Buildings could be 
qviickly erected and completed, thus saving interest on capital. 

In order to obtain taie economy, however, it was necessarv that the planning and 
designing, and also the method of carrying out the work, should be svsttm.-itical, and 
in accord with the general principles to be laid down thereafter. 

Systematical Progress of Work.— The steeh\i>rk plans should be re.ady several 
months before wjirk could be st.-irled on site, to allow for the time required for the 
ni.mufacture of tlie steelwork at the mills; also it should 1h' borne in mind that the 
steel could be obtained at ;i smaller cost if ajiiple tinu- were allowed for the steel 
contractor. 

It was advisable to order the full quantity of each section in one lot, and get the 
pieces cut to e.\act lengths ;it the mills. Considerable waste ix;curred if the shop had 
to draw mateiial from stock. 1 o take material from stock should only be permitted when 
very quick deliveries were absolutely essential. Cjenerally si>efil<in_g, complete dimen- 
sioned shop drawings should Ik" made in the office in preference to setting out the rivets, 
connections and details by workmen in the shop. Position of everv rivet should be 
shown on the detail drawings, and nothing should be left to the judgment of the 
workmen in the shops. .Another advantage of having complete shop drawings was 
that every piece could be inspected and compared with the detail drawing, and errors 
in shop work could more easily be detected than if the work were set out in the shop 
without shop drawings. Every piece could be made complete to the detail drawing, 
without fitting the different pieces together, and still thev must fit jjerfectiv when 
erected. The essential thing to remember in steel construction was that there should 
not be any alterations of the steelwork on the site. 

Manufacture. — An inspector should be appointed by the architect or engineer to 
inspect the quality of material at the place of manufacture. The inspector should be at 
the mills when the material was rolled ; also when the chemical and phvsical tests were 
made, and he should make records of the results of the tests, and order additional tests 
to be made if the material does not run evenly. The ins]:)ector should reject and order 
any material to be removed which did not meet the requirements of the specification, 
and should stamp and approve that which was satisfactory. 



SOCIETY OF ARCHITECTS. 



ICQNCBETEJ 



Shopwork. — From the sttx:kyard the material was brought to the workinjj shop, 
and skilled workmen marked the ]X>silion of the holes, lines of cutting, etc., on the 
steel pieces direct, with or without template. 

In the case of built-up sections, as, for instance, a column composed of angles and 
plates, all the angles and plates were not marked and drilled sejKirately, but onl)- a few 
holes were first drilled; the different plates and angles were then bolted temp>oraril)' to- 
gether, and the whole thickness of metal were drilled through at the same time, thus 
saving time, and assuring greater accuracy and all holes being true. 

During assembly the detail drawings should be consulted and dimensions checked. 
When the pieces were riveted they were .sent to the milling machines if anv part had to 
be machined, such as ends of columns or bearing plates on girders. Before assembling 
some surfaces must be painted, as after assembly they are inaccessible. Open holes 
which were to be filled with rivets in the field should be marked by the assembler, so that 
such holes had not to be filled in by rivets in the shop. Holes in small pieces and 
brackets were generallv ])unched .and riniered .after assembling, but main members were 
drilled. 

Before the finished steelwork was painted it should be examined by the inspector, 
and all dimensions checked. Ends of compression members which were machined must 
be examined, and it should be ascertained if the ends were square to the axis of the 
member. 

The m.aterial would then receive its shop coat of paint or oil before shipment. 

Erection. — The material was usually brought alongside the building on vans, and 
was hoisted by the erection cranes to a place on the building near to where it was to 
be erected, or sometimes directly placed in its final place. The different pieces were 
first temporarily bolted together and afterwards set to correct level and made plumb, 
after which all holes were filled with rivets. The steelwork should be painted 
immediately after erection, and if more than one field coat was applied, different 
colours of paint should be used. 

Floors and walls were then built and firejiroofing' applied. 

The erection of the steelwork should be two stories ahead of the floors. The floors 
should be put in one storey ahead of the walls as convenient. In cases where walls 
partlv support the flcK>rs or girders the walls must, of course, be built at the same time 
as the steel was erected. When the carcase was complete, and the roof on, heating, 
ventilation, etc., were installed, partitions built and joinery and finishing completed. 

It was wrong to suppose that after a good design and specification were made the 
responsible engineer's work was done. A good specification was of equal little use 
without inspection as a clever design without proper shop drawings. 

The practice of taking a few test pieces from a job and sending them to a testing 
firm was not reliable, and was more deceiving than convincing. It might be that the 
piece selected would show good results, while material in other parts of the structure 
was bad. The materia! should be tested at the mills during the progress of manu- 
facture. 

Calculations and Preparation of Plans. — When preparing plans and calculations 
for a building the work should proceed in the following order : 

1. The specification drawn up for stresses and loads. 

2. The principal members for the structure to